Performance carburetor

[PeteA216]

Dual exhaust will give you a little bit in the mid-rpm range, but don't expect a huge power increase. A stock 305 has fairly restrictive heads with small valves which is why they don't always do so well at higher RPMs. An exhaust will only help so much. I'm not saying don't do it, by all means go for it! Just don't expect to jump in the car and start spanking Corvettes on the 1/4 mile strip. Just remember, you do need some back pressure.

[mike561]

so in general whats the best thing to put into a 305 to get noticeable h/p gain?? i'd like to have at least 200 if possible

[silicon212]

Originally Posted by mike561

so in general whats the best thing to put into a 305 to get noticeable h/p gain?? i'd like to have at least 200 if possible

Forgive me but I am getting the strongest, most noticeable sense of deja vu here ...

Do the heads. Locate a set of 461 heads -or- an aftermarket set of World Performance S/R Torquer 305 heads. The latter come with 1.94/1.5 valves and ports/bowls designed for airflow. The heads alone, all else being equal, might be good for 45-50 HP. Throw those, along with a nice bumpstick (don't go overboard), duals and a good dual-plane intake on it and watch the 305 wake up.

However, it might be cheaper to stick a 350 in it, in place of the 305.

[mike561]

ok, i just wanted to get a good comparison, my pontiac grand prix i used to drive had about 230 h/p stock and it was a 3.8 V6, granted it had a factory supercharger as well though.

[Nalayah]

I don't mean to hijack your thread, but you made a comment of 200+ HP. What exactly is the stock HP on a 305 4BBL caprice? And is my low 0-60 a common thing?

[PeteA216]

Horsepower and torque of a 305 generally run about 165HP and 240 ftlbs, give or take 5 on both. Low 0-60.... oh yeah, back when I had a 305 in my '84 with no other mods aside from removed AIR pump and A/C compressor, I ran the 1/4 mile at low 18s, very high 17's if I was lucky and launched it right... pathetic, I know.

[SgtRauksauff]

When I had my '83 with a 305, it was an ok car, but just didn't have the oomph that it needed.

when the water pump bearing siezed up and the engine overheated, I threw in a 350 from a 77 suburban that my uncle gave me for free.

With no tuning or anything other than new plugs, wires, cap, rotor, and a non-leaky exhaust system with a glasspack, the 'ok car' became an awesome fun car. My mother drove it once, and even she said that it was really nice to be able to step on the gas and actually be able to pass someone...

Even with the 350 I was still able to get about 16-19mpg consistently, and I was only able to get about 22 with the 305 on it's best days...


--sarge

[PeteA216]

Y'know the old saying... "there's no substitute for cubic inches." stock 350s not only have more CI's but also come with better, higher flowing heads in most cases. The combination of the two is a surefire way to power. Mike, if your engine is running fine and you're happy with the power, leave the engine alone, as it is set up right now it's running at it's peak assuming everything is well maintained. If you're really interested in giving that car some get up and go, dropping in a 350 is really the best, easiest and most cost effective way to go. Even if you get a used, stock 350 in good shape mechanically you will be amazed at how the personality of that car changes. May people are intimidated by the thought of an engine swap, but it's really more simple that you'd think, providing you have a cherry picker (engine hoist).

[mike561]

yeah the engine is running fine, i do have access to a engine hoist. a 350 doesnt sound that bad of an idea either. do i need a different tranny for the 350 as well?

[PeteA216]

Well, you might want to beef it up in the future, but if the tranny bolts to a Chevy 305 it will bolt right up to any small block or big block chevy engine. So yes, to answer your question, your tranny will work.

[mike561]

Ok good to know, i considered doing a 350 swap in the past but i was worried it would be a big task and expensive.

[SgtRauksauff]

the biggest thing that I've run into when swapping engines in cars this old (finally broken in) are just rusted bolts, particularly on exhaust fittings. If you plan on plenty of time, and make sure you stay organized (keep your wires, hoses and bolts and such labeled and sorted (digital camera pics are great!)) it goes a lot faster than you think.

I was expecting to take a full day to get the 305 out, and another day for the 350 back in, and ended up getting the whole thing done in one day with just my father and I. So I spent the next day putting new cap/rotor/wires/plugs/belts on the 350, and rigging up the exhaust so it fit, and I was actually able to drive it to work on Monday morning! It was a neat change, usually I was the one helping my dad with his projects, but it went smoothly since we'd worked together a lot in the past.

Toward the end of it's life, after having the 350 in it for about 6 years, and upwards of 297,000 miles on the transmission, I finally cracked the flexplate. Otherwise, the tranny held up and shifted great!

Mine was the same color dark brown as yours, but not two-tone, with a vinyl top. I was using S-10 15x7 rims, every time I see your sig, I get cool flashbacks!

--sarge

[Blt2Lst]

Getting back to the carb.
What about playing with the jets and metering rods in the secondarys of the stock Q jet for better WOT performance.
I was wondering if this is worth the effort. I was about to do this in my 89 wagon with a stock 307 vin y engine and electronic Q jet.
Also installed a computer chip, not really sure if it made a big difference the car definitely lacks power for passing.
I was told to fatten up the secondarys for added WOT power but have not done it yet. This modification also keeps the car smog legal.

What do you think?

[mike561]

Originally Posted by SgtRauksauff

the biggest thing that I've run into when swapping engines in cars this old (finally broken in) are just rusted bolts, particularly on exhaust fittings. If you plan on plenty of time, and make sure you stay organized (keep your wires, hoses and bolts and such labeled and sorted (digital camera pics are great!)) it goes a lot faster than you think.

I was expecting to take a full day to get the 305 out, and another day for the 350 back in, and ended up getting the whole thing done in one day with just my father and I. So I spent the next day putting new cap/rotor/wires/plugs/belts on the 350, and rigging up the exhaust so it fit, and I was actually able to drive it to work on Monday morning! It was a neat change, usually I was the one helping my dad with his projects, but it went smoothly since we'd worked together a lot in the past.

Toward the end of it's life, after having the 350 in it for about 6 years, and upwards of 297,000 miles on the transmission, I finally cracked the flexplate. Otherwise, the tranny held up and shifted great!

Mine was the same color dark brown as yours, but not two-tone, with a vinyl top. I was using S-10 15x7 rims, every time I see your sig, I get cool flashbacks!

--sarge

yeah this is actually my second box caprice so its cool driving around in one again, last one i had was about 2 years ago

[beat88ls]

Originally Posted by mike561

yeah this is actually my second box caprice so its cool driving around in one again, last one i had was about 2 years ago

its kinda funny... my first caprice was an 88 LS Brougham, and my second is an 83... i really wish i still had that 88, so many good parts i could have stripped