SBC 305 power upgrades

What year 305? That's sorta important. I had a 1991 Pontiac Firebird Formula 305HO/5spd that bone stock was pretty quick. My little brother had an 89 GTA T/A 350 A/T... up to around 80mph my 305 would walk all over him and then cubic inches won. The last gen 305's with the better valvetrains and heads ran pretty strong and got great mileage.

(example from wikipedia)
Engine Summary (with corresponding RPO code):

• 1982–1983: LU5 5.0L V8, 165–175 hp and 240–250 ft·lbf
• 1982–1987: LG4 5.0L V8, 145–170 hp and 240–250 ft·lbf
• 1983–1986: L69 5.0L V8, 190 hp and 240 ft·lbf (330 N·m)
• 1985–1992: LB9 5.0L V8, 190–230 hp and 275–300 ft·lbf
• 1987–1992: L98 5.7L V8, 210–240 hp and 315–340 ft·lbf
• 1988–1992: L03 5.0L V8, 170 hp and 255 ft·lbf (346 N·m)
• http://en.wikipedia.org/wiki/Pontiac_Firebird#1991

If it's an "older" gen 305 read this 307 thread and it's links for smart cheap power. http://www.jalopyjournal.com/forum/showthread.php?t=204736 (so far I'm $575 into it... I picked up a set of "torquer" heads from a fellow HAMB'er for $500.... still gotta find a cam, an intake and a few other bit's and pieces... but my "goal" is to get around 300hp for less than $1500 after going through it.)

 

If anyone reading this thread wants a 305 out of a late model RS Camero..low mileage around 55,000miles. Pm me..probably $400 bucks could have it..or $900 for the entire driveable car.
car needs too much work to care about, and its not Traditional..so its just a donor car.
engine is still in the car, can here it run

sorry if this is in the wrong place..not going to list it in the want ads..its a fellow neighbor rodders pile.

if this post neds to go..shoot it to the curb IDC

 

Best band for your buck, see the link below

http://www.goingfaster.com/spo/carcraft325hp305.html

 

they got a jump from the smog exhaust to full performance exhaust. I assume the hot rod already has non smog exhaust. I just don't think the differnce between headers and stock manifolds is that great on weak stock motor. I have put just headers on and not gained much before.

 

I'd take a measley 307 over a 305 anyday! A 350 is the best though, for a small block in a hot rod!

 

307 is more apealing. 283 bore with a 327 stroke.

 

Amen cuz, plus those blocks are all old models and will look better in a hot rod than a later model block!

 

This always cracks me up! An out-of-the-box Holley 1850 600cfm vacuum secondaries carb is PERFECT for a stock or mild 305 engine! I've done it a few times and it's always been right on the money!

Here's a little secret for y'all: Carburetors meter fuel in proportion to the amount of air being pulled through them by the engine. In theory, the best ideal mixture is said to be about 14:1 (air to fuel ratio) at sea level. Whether ya got a 200cfm carb, or a 1050cfm Dominator, it should be calibrated to keep the air/fuel ratio at about 14:1 out of the box, no matter what engine you bolt it onto.

If your eyes are watering cause the mixture is too rich...you have the wrong jets, wrong power valve, or your float level is too high or some other problem/tuning issue. Now, running a "double pumper" carb on a stock, small displacement motor will tend to "dump" too much fuel into the venturis for the motor to handle when the throttle is mashed, producing a black cloud from the exhaust, but the jetting in the carb should still have the mixture in the ballpark.

It's like when people go the OTHER way...saying things like "Oh! That little two barrel is gonna make that big 400 cube motor run lean!" No it won't...unless it's calibrated wrong. If it's set up to meter the fuel at the proper ratio, the only thing a "too small" carb will do is to limit the engine's rpm potential...it'll "starve it for fuel AND air equally at wide-open-throttle, but the mixture will still be right...the motor just won't "pull" beyond a given rpm...where it "runs out of carb".

A carb "too big" doesn't run rich unless you did something wrong.

A carb "too small" doesn't run lean unless you did something wrong.

For the record, I've run 750cfm Double Pumpers on 305s before and they were not too rich. Of course, that car had a decent cam, open headers, a good gear, etc.

Yes, all things being equal, a 350 engine WILL out-perform a 305...but it's not as big a gap as some would have you believe. And honestly? 99% of you probably wouldn't be able to tell the difference from behind the wheel anyhow.

305s are the "new" 283, just like 350s have long been the "new" 327!

Build what ya got, or what you can afford...at the end of the day, it's still a small block Chevy and unless you announce to folks that it's a 305, nobody will know or care.

 

I would rather build a 283, 327 &350 than a 305. I have a 305 in my driver pickup. it's ok but for I wouldn't rebuild it