first time project, no experience

Hey I have a automatic 1978 Camaro type lt. It was a gift given from my dad when I graduated high school. I drove it for a year and then I parked it; however, I now want to invest a little money to get better performance. I want to swap the 305 8 cylinder engine to a 350 for more muscle, but if I can keep the 305 engine and add a few parts to the camaro, what would those parts be? Would you consider putting in rear end posi traction because at the moment it doesnt have it. I really need help. please consider the facts: I don't have much money to spend, I will be doing the laboring, and have no expirience in cars. Please let me know anything that is best for this situation, and consider all the facts that I mentioned, so please give me lots of details as possible. I would really aprreciate it and my father would be so proud if I just flipped the car into a beast or similar. Thanks I would really appreciate it.file:///C:/Users/CASTIL%7E1/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif

damn kid, i like that...you are going to get your hands dirty and spend your hard earned money on that project...i never had a 305 v8 and im not really sure what u could do with it..i hear alot of guys here talking about the 350 swap...and even on a tight budget im sure if u looked around u may be able to find alot of things for a good price....somebody with more knowledge im sure will come in and help u out, i wish u good luck on that project im sure your dad will be very proud when u are done! :cheers:

I have a camaro 78 with engine 305 8 cylinder and 2b carburator. I want it to run a lot faster than what it does. If I put a camshaft and a 4b carburator will that get me anywher. Or what should I do to add power to this machine.

Well, uasually I'm one to deffend the 305. But, in some cases, it's not the economical way to go. A motor swap is pretty straight forward. The problem is that it's all in the prep work. Ofetn times, the inexperienced will just start yanking wires and hoses thinking the new motor will be in an a hour and they will remember exaclty where everything goes. :(

This ain't NASCAR.

If you're inexperienced, stuff is going to break or get lost. If you're on a budget you're either going to get a deal or get screwed. 350's are a dime a dosen, and you could snag one from a 82-92 thrid gen, but again, not much power in those either in stock form.

My best and only advice right now, start small, get to know the car. Give it a full tune up, plugs, wires, cap, rotor, air filter, fuel filter and check over that chinese noodle bowl of vacuum lines for any broken ones. This will undoubltadly put a little pep back in it. Then you can get a little adventurous, play with the exhaust, a cheap investment. I do not recommecnd cracking the rear end open without someone who knows what they are doing. we could give you step by step detailed intruction, but none if it will be worth a lick when something unexpected happens.

EDIT - threads merged, a 4BBL and intake is something the novice can handle, again taking some time to note what cam from where!

To carry further what WrightZ28 has said, there are a couple other considerations.

Goals... Set specific goals for your car and yourself. Power output, driving style, handling, ride, etc. Be sure they are realistic.

Budget... Decide just how much money you have to devote to the project. MOST IMPORTANT!!! Be realistic with YOURSELF...

Stay on track... Once you establish a budget, make a plan to achieve your performance goals. Never "change horses in the middle of the stream". Making one change in your design can have a ripple effect on all the other choices you've already made, and a dollar effect having to buy stuff a second time because what you bought the first time won't suit the change you just made.

But yes, get familiar with your car BEFORE you start tearing into it.

Jim

my opinion on this, I already try with a 305, put bigger valves, bigger cam, edelbrock perfomer intake, 750 holley, shorty headers, posi rear end, msd super conductor cables, msd coil, msd 6a box, what happened? burned the 700r4, drop a 350 tranny on it, burned out too, and it didn't run like I was specting, so what was the next step, drop a muncie m22 with new cluth disk and pressure plate, then broke the engine, so my advice to you put some headers with dual exhaust, and leave the 305 stock or put a cam just for the fun of it, find a job, save some money, then buy yourself a 350 with a good pair of heads, a good cam and if posible stroke it, but in your and my case that would be a lorng term invesment, im telling you this because im only 20 years old and I have already been on that position, so please dont waste money with the 305 you will not be happy with his numbers
just my .02 cents

besides, although its only 45 cubic inches bigger, a 350, with a mild-hot cam will nearly double the stock outbut of the 305.

Again, albeit I am normally one to defend the 305, but in this case it might not be a option. But, again, diving into something like a engine change is for further down the road.

Plus gentleman, when someone is just learning, why learn on something that cost you a bunch of money and you know nothing about and probably learn a unexpected lesson (or two) the hard way? i certainly hope you don't learn and get accustomed to porting and polishing heads by ordering new ones and going to town on em :eek: Me, no, i had a warped worthless head from 3.8 Buick and developed my technique and learned on that befroe jumping on anything else. :2cents:

That said, ewrock, learn with what you have. Get yourself a nice detailed manual and read through each procedure BEFORE you do it, and make sure you have all your parts, tools, and are comfortable with what you have to do, and to guide you if you happen to hit a tricky spot.

You will come to find you can learn a lot about what's going on with your though simple maintnance.

Partwise for the ignition system, stick with what the doctor perscribed, good ol Ac/Delco parts. May be a little more up front, but worth it in the long run. On the radiator support or hood, you should find a decal that will list your tune-up specifications, and even corresponding Ac/Delco plug number and gap size. Compare this information to your manual for any service changes that may have been made.

The true thing to watch with plugs and wires is the wires. Do them ONE at a time. When you get your new wire set, lay them out you find them all to be of different length. For each old wire you remove, identify it's replacement by comparison length. NOTE - pay attention to how the old wire is routed from cap to plug before you remove it. Check all spots of the wire closest to the exhaust maniflods for any discoloration or flat out melting, this will indicate if you need to reroute the wire away from the heat.

Plugs, fairly straight forward, just be graceful on breaking the old ones free (no pun intended). You need to hold the ratchet straight and ensure it's fully seated on the plug evenly, if not, and you muscle it, then you are going to have huge problems. When you put the new ones in, set the gap correctly, a dab of antisieze on the threads, and snug em up, don't go crazy and get em super tight, snug is good (once the thread fully seats, just a little 1/4 turn and you're done) NOTE- You'll find this a nice trick, put each old plug into the the new one's box and label which cylinder it came from and hold onto them. They may come in handy later for diagnosing a developing problem as you are getting to know your engine.

The cap and rotor are stratight forward. most rotors and caps only go on one way with the BAT + and TACH pointed 90* toward the driver's side. Again, when replacing the cap, ONE wire at a time.

Once this is all done, check your work, test drive noting any difference in sound (turn the radio off :) ) or performance and if all is well, try and sneak in a cold one for job well done.

Then we'll move on to checking and setting ignition timing and the the fuel system.

Good luck and have fun :thumbsup:

what do you mean by caps and rotors?

Distributer for the ignition system.

Listen, This is my advice...Junk Yards are a gold mine at times!!!! Another mans garbage is another mans treasure!!! Plus you can get things pulled for you if u dont want to get dirty. You can learn how to take things apart in there as well. U can make mistakes there that wont hurt your project car. Purchase a manual and like the others said, get acquainted with the service procedures. I bought a 350 with the tranny for 175.00 with everything on the engine. Plus they turned it on for me b4 I took it. I sold it on ebay for a 100.00 and it was a High Output engine. Alot of young people wreck their cars and they wind up in the junkyard!!! I was there two weeks ago and saw a few 4th gens laying around..It even helps to suck up to the owner and grease him for any lead on a new camaro going into the yard. And remember Lt1's were made for taxi's and there are some of those in there. Another word of advice that could go a long way for you. Use the technical schools in your area. Alot of them do machine work and the whole nine for peanuts and crackers. Take your time and get lots of advice from anyone willing to help. Good Luck with that project! :popcorn:

a key thing to remember here, is that ALMOST any modification you do to the 305 is going to be something you can directly swap to a 350 core when you so chose to do so. I started off with a 305, and they can certainly be made to run. they are not high rpm motors because of valve shrouding and small ports, but at low rpms (lets be honest, thats really where we all drive on a day to day basis) they will put out plenty of grunt. More than enough to smoke most DD honda's all day.

My suggestions are to ignore big engine mods for the time being. really, you want to build your drivetrain up first anyway. if you drop a powerful engine in the front, you start finding the weak links in your drivetrain and chassis the expensive way... IE, things start breaking.

Two of the biggest seat of the pants improvements i made to my IROC were headers, and a rebuilt transmission with a stage two shift kit. the tranny is not a cheap way to go unless you have a "guy" to go to. one of the guys i worked with built mine for 200 bucks, with me supplying all the parts and the core. but normally expect to pay 1000-2000 for a built tranny.

headers on the other hand, are relatively cheap, and will be easy to do on your ride, and will be a direct swap to a 350 later. also look into aftermarket ignitions and coils. the intake swap, and a 4 barrel will definatly wake up that ride. and again, will directly swap to a 350 later.

something to keep in mind... to turn that 305 into a 350, all you need is a 4in bore block, and the correct set of pistons. everything else will swap over. even the crankshaft and rods.

the posi will definatly be a good upgrade. i recomend the torsen unit out of a fourth gen camaro. youll have to find out if your car has a 7.5in or 8.5in rear axle. i cant remember off the top of my head what a 78 would have.... come to think of it its probly a 8.5in... so the fourth gen torsen wont fit. but if you do posi, do some gears. 3.23 or 3.48 gears are plenty fun on the street, and will be somewhat decent on the highway with what im sure is a non overdrive tranny.

I have a camaro 78 with engine 305 8 cylinder and 2b carburator. I want it to run a lot faster than what it does. If I put a camshaft and a 4b carburator will that get me anywher. Or what should I do to add power to this machine.to the gas station faster

not necessarily, a q-jet will actually get better mpg than other carbs if you lay off the skinny pedal. but when the 2in secondary valves open.... good night.

Hey I have a automatic 1978 Camaro type lt...I now want to invest a little money to get better performance. I want to swap the 305 8 cylinder engine to a 350 for more muscle,...Would you consider putting in rear end posi traction because at the moment it doesnt have it...I don't have much money to spend, and have no expirience in cars. Please let me know anything that is best for this situation, and consider all the facts that I mentioned,...
you need experience. both working on cars and understanding what is important and what is not. that comes with time and can't be rushed.

the only way to get it is to read, listen to others, and do as much work as you can on cars in a general sense as far as being a general "mechanic" goes. once you have more experience and solid mechanical skills under your belt, then i'd start in on a project. not that there's anything wrong with a 78 Camaro, but a 78 Camaro would not be my first choice for a performance project.

cars are expensive, if you don't have much money, don't look for much in terms of improvement/performance with a low budget.

good luck.

the most rewarding thing you can do is save and plan. The 305 is junk and will never give you enough power. Your options for a motor swap are endless, but the cheapest is gonna be either a 350 or a 400.. I bought my 350 for 500 bucks off my wifes step dad. It's rebuilt and bored so it's really a 355. it's a 4 bolt from a early 70's car. I ended up selling my old 350 TPI motor for 250 bucks. they are dirt cheap! i say save up 800 bucks and find your self a really nice low mile 350. An even better move would be to locate a 400 cause those will give you tons more torque. The tranny should hold the power from the 350 so i wouldn't worry about that much. maybe install a shift kit and/or higher stall converter. The rear end is going to be your next enemy. Any open differential( no posi) is gonna hurt you bad, and if you have tall gears(low gearing like 2:73) then your really fucked. You need posi traction and some shorter gears. shorter gears are gonna help you accelerate better out of the hole. So you need to save a little bit of cash and get that 305 out.. don't waste a dime on the 305!

The 305 is junk and will never give you enough power.

Oh really ?!?! :rolleyes:

pretty much. for my standards anyway.. Check out gmhighperformance magazine. that had a project called blue thunder. It was a thirdgen formula with the 305tpi and a t5 tranny. they did like every bolt on from heads and cam to rocker arms, exhaust and a chip.. The thing barley ran a 13.9 with all that done. Theres another project car i read about that was a camaro z28 with a 305 tbi. That thing was just pathetic, they did everything they could to that thing and it went from like a 18 sec 1/4 to like a 16.8 NA and then they sprayed and ran a high 13sec 1/4. Now i'm not saying someone else can't do better, but why waste all that money on making a 305 run 14's when you can buy a 350 and run what ever you want. Doesn't seem practical to spend more to go slower. I'm sure theres a few nasty 305 builds out there that are quick, but to me thats just pissing money away. I'm not just some magazine Quoter either i've seen how bad 305's suck in person..

Beauty is in the eye of the beer holder...

Just like my favorite engines, the traditional Pontiac V8s, 305s are victims of myth and superstition. We hear all the time, how "you can't make a Pontiac run. The only way to make that GTO fast is to use a Chevy motor..." Yah, right. We have a street-performance package for the Pontiac that makes an honest 600 horsepower, 650 lb. ft. of torque, idles in gear at 800 RPM with 14" of vacuum, gets 14 MPG at cruise, and moves a 3,800 lb. Firebird into the low 11s in street trim, all on 93 octane gas. Hard-pressed to find a BBC that can match that under 500 CID.

One of my best friends has an '87 IROC with a TPI 305 in it. Bored .030", it has the old "601" 305 HO heads on it (with significant port work, but still...), a Comp hydraulic roller, 5-speed, 3.42 rear. It makes 355 RWHP. That's at least 400 at the flywheel. It crusies at 1,800 RPM and makes 26 MPG. It goes low 13s with the street tires. Slicks would put it solidly in the 12s. But we don't read magazines, we build engines and cars. GM Performance is VERY limited, as they use, pretty much exclusively, GM parts. Comp has better cams. Dart has better heads. (for example, there are others)

There was a class in the '90s for sprint cars, called "E-Class". They were mandetory 305s. 3 3/4" bore, 3.48" stroke, 5.7" rod, NO EXCEPTIONS. A .020" overbore WAS approved, but frowned on. With high compression (12.5:1), they made well over 500 horsepower on methynol, mechanical injection, no "adders".

NEVER say "never"... The most common mistake made when building a 305 is using the wrong heads. If one uses an intake valve larger than 1.84" in diameter, power loss occurs, as the mixture rams straight into the cylinder wall. Perhaps that's why Chevrolet never put 1.94s in them.... HHHMMMM....

Not to be sarcastic, but ANY engine can be made to make good power for it's "size" (displacement). One must simply "tune" to the strong points and avoid the weak ones. 305 is a small block Chevy. There are no small block Chevys that CAN'T be made to perform as well or better than any other engine in their class. As much as I love the old Injun, this is the plain truth. Even the 400SB, which by most standards is a POS for durability, can be made to make more horsepower than the venerable 400 Pontiac. Of course, unless you use aftermarket block and heads, it won't "live" or flow. The block is the weakest part of a 400SB. Also, at street-power levels, the Chevy won't outperform the Pontiac. Torque is "king" for a street engine and the Pontiac is the torque "king" of the GM muscle engines (reality, not magazine numbers). With the funny bore/stroke ratio of 305, it makes a fine torquey engine. And it can be revved to the moon, just like 350 (same rod/stroke ratio), if all the necessary hardware is installed. It won't make the same high-end power 302 (Chevy) will make, but it will make a lot more low-end.

I'm with wrightz28. 305 has it's place in the pecking order...

Jim

I'm sorry, but a streetable 305 making over 400 hp at the crank is a big pill to swallow. Some years back Car Craft did a build of several 305's and the best they could get was 329 crank HP from a 334 stroker on pump gas. If you want to make HP you need displacement, plain and simple. For the money you'd dump into a 305 to get anywhere near 350 HP you could take a 350 well on its way to 500. ANYTHING you can do to a 305 to make more power can be done on a 350 and will almost double the results and usually for LESS money.
NASCAR is limited to 305 CID also, I believe. But if you think that is the 305 GM produces...wrong.
Running astronomical compresion isn't really an option, unless you have access to methonal and nitromethane..then again that isn't "streetable" either.

And whoever thinks a Poncho can't make power has obviously never heard of a 389 Tri-Power, 400 R/A IV, or a 455 SD.
The Pontiac engineers were able to get the SD to 600 HP using off the shelf GM parts that anyone could buy at their nearest Pontiac dealer...If that ain't power, I dunno what is.

besides the bore which other diference is between the 305 and the 350??? every thing else can be swaped from one to another

besides the bore which other diference is between the 305 and the 350??? every thing else can be swaped from one to another
Heads. The 350 heads generally don't fit the 305 because the intake valves either hit the cylinder wall or are shrouded. And 305 heads on a 350 can cause too high compression and quench area problems. Also, the crank in the 305 is balanced differently, even though dimensionally it is identical to the 350's.

Screw 305.. just go with a 350.

Perhaps you missed my statement about not reading magazines. We don't care. They are in existence for entertainment and selling advertising space. I invite you to Virginia Motorsports Park and we'll be happy to demonstrate the 400-plus HP 305. We don't race dynoes. We don't race flow benches. We don't race magazine articles. We race CARS. Just because a few "journalists" and their chosen buddies can't make 400 HP from a 305, doesn't mean it can't be done. It means THEY can't do it.

Glad to see you're aware of Pontiacs, but we still get the statement. We still see magazine jerks sticking craters in old GTOs and LeMans'. We still read where THEY can't get Pontiacs into the 10s in street trim. But it happens every week. You aren't foolish about Pontiacs. Don't be foolish about 305s... I've even seen 307s go into the 12s in '69 Camaros, and 305 may have better parameters than 307.

I don't disagree that 350 will make MORE at the same level, but 305 is hardly "junk".

Jim

eh, i still think it's just easier to go get a 350 and be done with it. Unless theres something to be proven or a statment to be made, don't bother with the 305..

plus think about the situation at hand. this kid with the 78 camaro is still learning, we gotta help him in the best way possible and to me the easiest thing for him is gonna be motor swap. shouldn't take more then 1 day to do. thats not knowing what your doing of coarse. motor swap all day long!

p.s. a motor becomes junk when you dump hard cash and see minimal power gains. in my opinion..

eh, i still think it's just easier to go get a 350 and be done with it. Unless theres something to be proven or a statment to be made, don't bother with the 305..

plus think about the situation at hand. this kid with the 78 camaro is still learning, we gotta help him in the best way possible and to me the easiest thing for him is gonna be motor swap. shouldn't take more then 1 day to do. thats not knowing what your doing of coarse. motor swap all day long!

Okay, we get your opinion of the 305 for what the 4th time. :disappoin

Unless you were born into a family bloodline of gearheads, were you able to do your first motor swap in 1 day, not knowing wnything about cars and no help? Please don't bother to type "yes" :bs:

Edit, again, he ahs no experience, and little funds, best to learn on what you have.

just trying to sway him away from wasting his money and being disappointed.

Motor swap isn't hard, especially if your going from a 305 to a 350. I'm not saying i'm amazing with cars or anything either, but everyone has a buddy thats good with cars. I did my first motor swap on my 91 formula last spring with my wifes step dad and my brother in law. we weren't in any hurry and we did a lot of other stuff at the same time, but we had one motor out and the new one in with 5hrs time. toughest issue we had was lining up the motor with the tranny.

Make friends with a gear head and have him help you do the swap. it's easy.

I really need help. please consider the facts: I don't have much money to spend, I will be doing the laboring, and have no expirience in cars. Please let me know anything that is best for this situation, and consider all the facts that I mentioned,

Young kid wanting to learn and to impress his father. As a father, I would/am be much more impressed with my one of my sons who took the time to learn about mechanics and rebuild/improve, versus just throwing a new motor at it. Anybody can unbolt parts (hell my youngest was doing plugs at 5!), but to learn to know how each one plays into the entire picture of the motor is what developes knowledge.

true, but in reality 3 or 4 yrs from now it's gonna be a slow 78 with a 305 in it. It's one of those things.."if i only knew then what i know now".. throw in the 350 and learn with that and save yrs of your life lol

Dosen't really matter what some pro engine builder can eek out of a 305, for his purposes it has to be streetable, those aren't.
The bottom line is; dollar for dollar you will always get more power from a 350 than a 305.
For what he'd need to spend to get some real power from his 305 he could put in a 350 and end up with the same power AND the potential for a whole lot more.

not only that but the 350 will be more reliable then some strung out 305 ready to pop... hands down do the 350 swap. we'll help you through it with any questions you may have.

Perhaps you missed my statement about not reading magazines.
Perhaps you should have read their article. CC isn't about building all out money-no-object cars & engines. They are more about what the average Joe can and does build and within a set budget....Who cares? Me for one. I don't have an unlimited budget and I don't know anyone who does.

Morely,

I understand your point, but magazines are supported mostly by their advertisers, not their readers. After 30 years of building engines for real people and real cars, I'm fully aware of budget constraints and various "levels" of builds. It has been my experience, magazines rarely have (or use) current information and rarely use anythig NOT "mainstream", while racers and streeters are always trying to "press the edge", even when the budget restricts them to a certain level.

Again, just because a writer says "that's all there is" or "it can't be done", doesn't mean it's so. We've had one recently, where another shop told one of our our customers flatly, "You can't get more than 270 CFM from that casting no matter HOW you try." This is a shop that is regularly featured in High Performance Pontiac Magazine. We routinely ship that same casting out at 285. This is the same mentality that honestly believes CNC porting makes more power than "hand" porting, and it just "taint so"!

I'm not saying YOU'RE wrong, I'm saying there is more to it than you may understand. LOTS of good engine guys ot there beating up on the "big names" every week. You never heard of them, and probably never will. That doesn't deminish their skills.

Jim

ewrock- what are you thinking so far given whats been said?

an engine swap is hardley something i would recomend as a first step for someone looking to learn how to wrench on cars.

and for the record, modifying a 305 from stock is NOT a waist of money. its a stepping stone.

even if he decides to upgrade to a 350, any money he invested in his 305, from headers, to an aftermarket ignition system, to a windage tray oil pan, to a K&N air filter, is going to transfer directly to a 350 in the future. exactly where is the waist in money there???

someone just learning to spin wrenches shouldnt bite off more than they can chew. small steps, working up to bigger things, getting familiar with the car they have, is far more valuable than just "throw a bigger motor in it".

and no, the 350 is not always a better option than the 305, but it does hold the edge in higher rpm operation because the bigger bore allows larger valves and less shrouding. but by the same logic, you could suggest that everyone just run a 400 block because its obviously far superior to the 350 block.

crate motors are the easy way out. run what cha brung, and be proud of it ;)

In order to make any kind of power out of that 305 he's gonna need to get into the engine. he's gonna need better heads, better intake and a bigger cam. without those any bolt ons aren't gonna do crap unfortunately. And if he buys headers for the 305 they can possibly switch over but with a 350 he may wanna go with bigger piping. I mean if he wants to spend couple grand on bolt ons to gain 10-20hp then thats his deal. To me going from 17.8 down to a 16.5 after spending 2 grand is stupid. There comes a point where you just gotta realize it's a complete waste of time and money. maybe a different 305 in a different car can do better. Best 305 car i can think of would be a 90 formula t5. lighter body, better 305 with fuel injection and a better tranny not too mention better gearing. Starting with a 2nd gen, known to be heavy, and a 145hp 305 is a dead end. It will be hard just to squeeze 200hp out of the thing... swap for a 350 it's the only way.

"run what cha brung, and be proud of it"..

Thats ok in some cases, but not when you have something this guttless. how can you be proud of a car that is so slow and has no potential. be like driving your grandmothers 78 caprice wagon to the track. You'd look like a fool. Only thing his car has going for it is the fact that it's a camaro. Do the name justice and drop in a better motor.

An engine swap in a 3rd gen is a snap. I had mine out in around 5 hours, that includes unhooking everyhting from wires to exhaust to torque arm and driveshaft (took engine & trans out together).
If it is a TPI engine then there's a ton less wiring and vacuum hoses to contend with, unlike a carbed engine.
I'd have to say that the TPI engine swap (305-350) is about the easiest I've ever done. The new engine went in and was hooked up in about 6 hours and was running by the 8th hour.
SOME boltons would be swapped from the 305 to the 350...headers are questionable. The 1 5/8" primaries used for 305's would become restrictive in a well built 350, conversely the 1 3/4" primaries used for most 350's would be too large for the 305 and would hurt performance.
A 52mm throttlebody on a 305 is a waste of money too, there is no way that 305 is ever going to need/use that much air, and again it could actually hurt performance by slowing the incoming air.
The stock HEI ignition system is more than enough for a 305 and even for most 350's. If you want to upgrade in this area, get a set of Accel (or other brand) sprial core wires. They give better transfer of energy to the plug. Also you might want to get rid of the stock type bakelite cap and rotor and put in an Alkyd plastic set with copper terminals (Accel, Moroso, Taylor, etc). This will really perk up the ignition system.
K&N filters, while a good investment, aren't going to give you a performance gain (ok maybe .5 hp).
The 2 things I would recommend would be a good 3" cat-back system and maybe a cold air induction, unless it is the Camaro's TPI inlet. For the Camaro inlet you just need to remove the baffles that sit under the 2 filters.
Until you go for a 350 it is best to stay away from things like siameased runners, larger intake or larger throttle body. While all of these items seem like they would do you some good, pretty much the opposite is true. Larger openings mated to the smaller valved heads of the 305 would just cause the air velocity to drop and possibly cause stagnation which means the cylinders won't be getting a full air charge.
If you want to do some good in the intake area, pull it apart and port match all of the pieces and look in the passages for any flashing or other obstructions and grind them down (dremmel tool).
With all of these small, simple "mods" you could gain 10-15 HP on a well tuned 305. This will give you some experiance with engines and tools, won't be a big investment in parts and will give you the satisfaction of having done the work yourself.

he's got a second gen though. and it's already carbed. dropping in a 350 is sooo very easy. i mean if you wanted to you could just swap blocks and use the 305 heads. some backyard gear heads actually throw 305 heads on to raise compression. it's a dirt cheap mod that gives a little power. So really you could get away with just a the short block. Carb engines are twice as easy to swap then fuel injected engines. theres no wire harness,injectors, sencors, yata yata. in fact in my engine bay all i have are these:

motor
kickdown cable and throttle
wire to alternator
wire to starter
few wires going to firewall for interior stuff
two vacuum lines

it doesn't get more simple then that. if he just swaps the block he can easily do this in 4hrs. very very simple. do the swap man it's worth it and you will not regret it. other wise your gonna have to shell out mega bucks to make any power.

Sorry, I thought it was a 3rd gen for some reason. A 78 is going to have the mass of vacuum hoses in and around the carb. When I went to rebuild the carb on my 79 T/A I was pulling my hair out trying to figure out how I was going to remember where all of those hoses went. I finally came up with the idea to take testors model paints and paint the end of the hose and the barb it came from the same color, swithcing colors for each hose (took a lot of different colors)
I have to say that I'd rather change the engine in my 85 IROC than the one in the 79 T/A. I put headers on that car and it was a daunting task to say the least.
The heads on his 78 305 are going to be some of the worst castings GM made (next to the swirl port ones) and I wouldn't bother putting them on a 350.
I would look around in auto trader or the like and see if I could pick up a complete 350 for a good price.

good place to look for engines is craigslist. i always see 350's on there. I actually sold my L98 off thirdgen.org for 250 bucks.. The engine thats in my formula now i bought for 500 bucks rebuilt, so i'm sure you can find a 60k engine for 400 or a little less. Yea i bet the heads on his motor now are really bad, and getting some different heads wouldn't cost very much.. You can piece together a pretty decent motor just using factory parts. i actually wish i kept my l98 heads cause they flowed better and would have raised my compression.

LT1 265-285hp: http://rochester.craigslist.org/pts/641783867.html
350 complete: http://rochester.craigslist.org/pts/641266132.html
350: http://rochester.craigslist.org/pts/612977367.html
350: http://rochester.craigslist.org/pts/594536718.html

these were in my area, but theres good deals out there for cheap. You know what it would take to get 275hp out of that 305. a lot more then 600 bucks.