engine swap? 305 for 350

Hi, Im new to the forum but it looks like you guys give real solid advice, and thats what I need.

I have a 91 Caprice I bought at a police auction for $450 :evillol: The origional plan was to get it running good and then sell it. But I like it so much that I want to keep it. Its got a 305 with 245K miles, smokes a little and leaks some oil. I think i want to throw a 350 in there if its not too much trouble. Increased horse power would be nice. I dont like driving a car that doesnt have muscle. What kind of problems will I run into? will the transmission work good with a 350? what about all the hoses and junk?

I was thinking about buying from this site

http://www.rebuilt-auto-engines.com/cgi-bin/webc.cgi/buy_engine.html?p_vid=5388

anyone ever do business with them before?

http://www.rebuilt-auto-engines.com/images/gmc-305lb.jpg


"Additional performance options are available for most engines. To request additional options, simply type 'I'd like additional options' on the comment field located on the order form and we'll contact you with the list of options available for this engine before we build your engine."

What kind of performance options should I be considering?

$1300, no way. You could find an lt1 for cheaper than that.

$1300, no way. You could find an lt1 for cheaper than that.

I read that you have to swap the transmission for an LT1?

hook me up with a link dude. Im new to this...


What about this one? http://www.high-performance-engines.com/ce09.html

thay have free shipping...

$1300, no way. You could find an lt1 for cheaper than that.agreed. You could get an LT1 , work on the tranny some, and new gears for the rear end (well, maybe not new, but pretty close to it if you do the work yourself and shop around first) for that!

do you want an lt1 or just a 350 tbi?

agreed. You could get an LT1 , work on the tranny some, and new gears for the rear end (well, maybe not new, but pretty close to it if you do the work yourself and shop around first) for that!

I dont know how to do all that. I dont want to go in over my head. Looking for something simple. throw it in, bolt it on, drive away. know what im sayin?

do you want an lt1 or just a 350 tbi?

I dont care, I just want something with more power then the 305.

not looking to race or anything. just want a car that has balls.:smokin:

I dont care, I just want something with more power then the 305.

not looking to race or anything. just want a car that has balls.:smokin:

Get a 350 TBI, and a knock sensor for it. replace your PROM with one for a 350 although the 305 will work, you won't get the most out of the 350. Your transmission might not be up for the 350 though - I believe it's a 200-4R - you can beef it up or replace it (and the driveshaft) with a 4L60/700R4.

Get a 350 TBI, and a knock sensor for it. replace your PROM with one for a 350 although the 305 will work, you won't get the most out of the 350. Your transmission might not be up for the 350 though - I believe it's a 200-4R - you can beef it up or replace it (and the driveshaft) with a 4L60/700R4.

Sweet, thanks man.

So you think I could throw this in there? http://www.high-performance-engines.com/ce09.html

and just get a knock sensor? and it should work with my transmission? Everything should fit? Do you know of any good places to get 350 tbi engines?

Get a 350 TBI, and a knock sensor for it. replace your PROM with one for a 350 although the 305 will work, you won't get the most out of the 350. Your transmission might not be up for the 350 though - I believe it's a 200-4R - you can beef it up or replace it (and the driveshaft) with a 4L60/700R4. The 200-4R should be fine with a little work. The Turbo Regal's and GNX's used a performance version of it without trouble.

If you don't know what you're doing, you might as well skip the engine swap IMO and just beef up the 305. Contrary to popular belief, with a little work, that's one heck of a motor and should be able to blow away a 350 TBI with bolt-ons.

Also, if you want to accelerate faster, get lower gears. They help ALOT. I recommend 3:23's to 3:73's depending on how much you care about top speed and gas milage. Be sure to get the B&M WOT OD kit while you're at it.

The 200-4R should be fine with a little work. The Turbo Regal's and GNX's used a performance version of it without trouble.

If you don't know what you're doing, you might as well skip the engine swap IMO and just beef up the 305. Contrary to popular belief, with a little work, that's one heck of a motor and should be able to blow away a 350 TBI with bolt-ons.

Also, if you want to accelerate faster, get lower gears. They help ALOT. I recommend 3:23's to 3:73's depending on how much you care about top speed and gas milage. Be sure to get the B&M WOT OD kit while you're at it.

Well the 305 im running leaks oil and smokes and its my transportation so I dont have the time to take it out and rebuild it. I think replacing it is a better option. If im already going to replace the engine why not throw a 350 in there? its not that much more expensive... I have a friend that does alot of work on cars and he says he'll help me put it in. I just dont want to run into any suprises that stop me from getting the car going and i dont want to make it a huge burden for him trying to figure out all this junk that doesnt fit/work right when it comes time to do the job.

ok. Get a 350 TBI from a camaro or caprice and rebuild it. It should be a no brainer to drop that in, but it will still take the better part of a weekend to do the swap if you're lucky. Personally, I suggest you get new gears in the rear-end first. That doesn't take long at all and makes a huge impact on performance, plus you can upgrade to POSI (limited slip) at that point.

ok. Get a 350 TBI from a camaro or caprice and rebuild it. It should be a no brainer to drop that in, but it will still take the better part of a weekend to do the swap if you're lucky. Personally, I suggest you get new gears in the rear-end first. That doesn't take long at all and makes a huge impact on performance, plus you can upgrade to POSI (limited slip) at that point.

Like this? http://cgi.ebay.com/ebaymotors/IMPALA-SS-CAPRICE-TRUCK-8-5-POSI-3-SERIES-30-SPLINE_W0QQcmdZViewItemQQcategoryZ33731QQitemZ8034 334237QQrdZ1QQsspagenameZWDVW

The GM regular production option number for the 350 TBI engine you want is L05. Any car with an L05 in it would make a good donor car.

The TH200-4R that comes behind 305s is missing a plate on each clutch pack vs. one that works for HP use (the GNX, turbo GNs etc) and won't live too long behind the torque of the larger engine - experience prevails here. As far as it bolting up - the TH200-4R will bolt to any GM 90-degree V6 or any GM V8.

Also, the 305 can be modded but when it comes to brute force torque, there's no substitute for cubic inches and the mods you do to a 305 to get it close to a 350 will also work on a 350, pushing it higher. I've built several of each - basically it comes down to this - the 305 is a better economy engine than the 350 is, but the 350 powered car is much more fun to drive.

You can always build a 327 and have the best of both worlds. Use a 350 block, a large journal 3.25" stroke crank (found on CHEVROLET 307 engines, not Olds 307s used in the 80s) and some 327 aftermarket pistons.

Getting back to topic, the L05 is the engine you're after. They always came bolted to a 700R4.

The GM regular production option number for the 350 TBI engine you want is L05. Any car with an L05 in it would make a good donor car.

The TH200-4R that comes behind 305s is missing a plate on each clutch pack vs. one that works for HP use (the GNX, turbo GNs etc) and won't live too long behind the torque of the larger engine - experience prevails here. As far as it bolting up - the TH200-4R will bolt to any GM 90-degree V6 or any GM V8.

Also, the 305 can be modded but when it comes to brute force torque, there's no substitute for cubic inches and the mods you do to a 305 to get it close to a 350 will also work on a 350, pushing it higher. I've built several of each - basically it comes down to this - the 305 is a better economy engine than the 350 is, but the 350 powered car is much more fun to drive.

You can always build a 327 and have the best of both worlds. Use a 350 block, a large journal 3.25" stroke crank (found on CHEVROLET 307 engines, not Olds 307s used in the 80s) and some 327 aftermarket pistons.

Getting back to topic, the L05 is the engine you're after. They always came bolted to a 700R4.

So, you think I should go to a junk yard and get a L05 w/ trans attached? How do I know its going to work?

So, you think I should go to a junk yard and get a L05 w/ trans attached? How do I know its going to work?

You don't automatically, but you can have them perform a compression check on the engine. That, and a general look at the condition of the oil and transmission fluid will tell a lot about the condition of the engine overall. As for the transmission, that's the best way to do it but the 700R4 will require either you shorten the existing driveshaft by about 2" or so, or you obtain a proper driveshaft already made. Have them pull the pan off of the transmission with you present so that you can look into it. A little metal is normal but if you see large flakes or a pile of stuff, avoid it. You also want to see fluid that is bright red to orangish-red and doesn't have a strong smell. Strong smelling, cloudy, dark, brownish or black ATF is an indication of transmission overheating (either torque converter slippage due to TCC failure or internal transmission slippage) and you'll also want to avoid it in that case.

Concerning the link: I don't know if that's what you need for your car or not. If it does fit, that's just the carrier so you'll still need the gears.

I also fully agree with Silicon212. I said to beef up the 305 at first because I was trying to prevent you from having to remove the engine. But, as you said, it looks like it would need a total rebuild anyway, you might as well go with the 350. If you decide to rebuild the 350, and I would while it's out of the car, get the block machined and build a 383 stroker with ported & polished 305 heads. DON'T USE TBI HEADS. They are some of the worst flowing heads ever produced; they're great for low end torque, but terrible at producing high revving power.

also, take Silicon's word over mine. I know my computer **** like the back of my hand, but when it comes to cars, I'm still learning.

thanks. you guys are alot of help. I have another question...

Since it seems like im going to have to swap the transmission and engine to put in an L05... How much more work would need to be done to put in an LT1 vs L05? Would it be worth it? I mean... 260HP sounds pretty decent :wink:

thanks. you guys are alot of help. I have another question...

Since it seems like im going to have to swap the transmission and engine to put in an L05... How much more work would need to be done to put in an LT1 vs L05? Would it be worth it? I mean... 260HP sounds pretty decent :wink:

You will have to use the exhaust off of an LT1 Caprice in that case, which means true duals so it is worth it in that case, but you will also have to replace your computer and harness (try not to get the '96 if you do this, the '96 uses OBDII which has even more sensors and stuff, more work) and you will also have to replace your fuel pump with an LT1 pump. If you have the time, money and patience, the LT1 is where it's at.

The LT1 also bolts to a 4L60E which has computer controlled shifts ...

Ok Ill keep that in mind.

also one guy said to me, "you might be able to swap in a carburated 350 and it will save you alot of hassle."

Is this a good or bad idea?

I'd keep the EFI. It's much more reliable & hassle free overall.

also one guy said to me, "you might be able to swap in a carburated 350 and it will save you alot of hassle."

That person sounds like another one of the those people who missed the last 50 years. Electronic Fuel Injection (EFI) is the present and has trumped the carb for many years now. In 1989, when the Caprice 350-cid went from a 4-barrel to EFI TBI and had a boost in compression, the engine output rose and, despite a lower gear ratio (3.42 replaced 3.08), it got better mpg and a higher top speed.

These are the reasons EFI is superior to the carb:
http://www.tpub.com/content/construction/14264/css/14264_140.htm

Yeah, EFI might seem intimidating at first, but then so would a carb to a person who has never seen, let alone, worked on one. Those who rip out their EFI for a carb do so out of ignorance.

Ive been drooling over this engine for a couple days now... http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=8034486558&ssPageName=MERC_VI_RSCC_Pr2_PcY_BIN_Stores_IT

thaught you guys might like it... I seriously doubt ill be getting it though :frown: due to the price :banghead: . but it sure looks nice. 310HP :naughty:

http://i6.ebayimg.com/01/i/01/da/b4/ba_12_s.JPG

I was at the police auction today and they sold a 94 9c1. It was wrecked with frame damage and busted radiator but the engine looked good. I was prepared to pay $200 for it but it ended up going for $375. Now I'm kicking myself! I should have bought it for $400! :banghead: