Hey guys, I currently own a 1988 Firebird Formula. Its got a 305 with TPI and the 5 spd. I have a choice to make. I want to make it faster, so I either want to build a 383 fully tuned (aroudn 5 grand for the whole engine + new tranny) or I can rebuild the 305 and supercharge it (no idea on cost) What would you guys recommend? Either way, I want the T-45 (or is it T-56) tranny - the 6 speed - and am doing a lot of work on my car. Please help me with the pros and cons of each, price of super, and a guesimation of power and torque when both are compared. Thanks guys!

I think you will be a lot more happy with the 383 build-up. If you re-build a 305 and supercharge it, nothing against 305 owners, but you will still have a 305. You definatley will get more horsepower and torque from the 383. If you build it right you could have anywhere from 350-450 horsepower and probably right around 400-450 ft. lbs. of torque. And it is the T-56 (6 speed). I hope this helps. (strictly my opinion of course)

I've done alot of research on the subject. I finally decided to go with a 383 and then supercharge that. It will give me the more HP for the $ than the 305 will.

You can get great results from a 305 buildup. But as the old addage goes, There is no replacement for displacement. So naturally the 383 wins.

I am going to get my 383 as a crate engine. 388HP 480TQ YEAH BABY!!! :rockon:

i didn't think i was ever say this to another man but.... STROKE THAT BIT*H!!! LoL Get a :hail: 383 stroker:hail:

:rockon: chevy 383 storker:rockon:

well i have a rebuilted 305 and it's dead slow. I'm also looking into a 383 swap. something that has to be emission legal. I have some websites that has either short block and long blocks for sale. www.golensengineservice.com

well heres my problem. See, a rebuild of a 305 at 8.5 compression is roughly 1 grand even for me. Then id throw in new cam, new lifters, new rollers, new heads (edelbroke) and a new intakem, 1600-2000 total. Super charger im not sure on the price. Thats like 3500-4500 TOPS.

The 383 is a different story. Thats 3100 for the shortblock ALONE, plus 900 for heads, 350 for intake, etc etc etc, thats a LOT. PLUS it prolly wont be smog legal (difficult to keep it smog legal) and I'll be using way more gas. But the power is insane.

So I was wondering if anybody had any power figures, like a 383 produced X amount of HP and Y amount of torque, while a 305 super with this super has this and with this super has that. Make sense? I kinda wanna compair. To be serious, I live in california, where the smog laws are fierce and gas is expensive, so a supercharger is sounding nice.

Course I could always go twin turbo...

For those who have to deal with emissions. Why not go LS1? 300-335 RWHP out of the box and emmissions legal. Before you claim it's too expensive click this link.

https://www.thirdgen.org/techbb2/sho...hreadid=183547

~50 + hp 383s make over a 350

Im just trying to get the most power for my money here. Almost everybody is telling me to get a 383, yet some say the 383 supercharged is good. I dont want to REALLY make this thing a race car, just a street racer for fun car. its either a 383 or the supercharged 305. I'm thinking the 383 might be a little better choice.

How hard will it to pass smog with that motor?

Anybody know of a good online shop to get one built? Ok thanks

Astroturfhead, I'd go with the 383 all the way. I say this for two reasons. #1: My old man has one in his 73' Chevy Blazer 4x4. He took it to the local hot rod shop for dyno and produced 464.8 HP and 567 ft. lbs. of tq. $1900 for the short block(B&B). $1400 for the Holley Systemax kit and $300 for the Holley 3310 Double pumper. #2 I'm building one for myself and its not costing me an arm and a leg. I bought a used 350 from a tow company for $200. Rebuilt it for $320 and got the 400 crank off ebay for $189. Got the Systemax cam for $207. But all this is just my personal opinion.

the super charged 305 sounds like a fun project but the 305 has one HUGE draw back. the bore is too small for any top end power to be made with out killing the low end. you can only stick a certain size valve in that chamber and i think that is like a 1.86 which came on the HO motors. yes you can SQUEEZE a slightly larger valve in there but then the cylinder wall is shrouding the valve. they have used the TWISTED wedge heads with decent results. now a 307 or even a 302(larger bores 3.875 and 4.00) would be a better choice for the supercharger(i like the 302, and yes chevy made a 302 for 3 years). its very easy to make a 302, find a 350 block and buy the 302 LARGE jurnal crank, and pistons. the reasons i like this motor "stupid" charged is because of the short stroke which keeps piston speed down and also makes it easier to fill the cylinders in the given amount of time the valves are open; plus the small displacement makes it "good" on gas if cammed right. if you plan on stupid charging it use a cam ground on 114-116 lobe seperation. and if you can aford it have an oversized EXHAUST valve put in it and then pocket ported. this is a much better solution then just buying a cam with 10 more degreas of duration on the exhast; you'll make more power across the whole RPM band with a single patern cam and an EXCELLENT flowing exhaust port , if your stupid charging it; this also goes for NOS too!!! the wider lobe seperation will help emissions as well as work excellent with a super charger or NOS.