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I'm looking for some simple and reasonably cheap ideas to pep up an old 305 v8 I have. I don't want to put a lot of $ into it because one day I would like to put in a 350 or 383. I have a 55 Chevy 1/2 shortbed with NAPCO 4x4 and a 4-speed. I need a lot of low end torque and enough HP to move this monster down the road. I am looking into swapping the 4-speed with a NV4500 5-speed. It currently has a bad 2brl carb. Thanks. Michael

It's amazing what you can do with the small block Chevy and there's all kinds of books out there on the subject. I just purchased a book called How to Hotrod Small Block Chevys by Bill Fisher and Bob Waar and covers everything from 265s right up to 400 small blocks including your 305 and has some articles on how to bump it up on the cheap. Even part numbers for cams, carbs etc are in it and the interchangeability of the parts. It's amazing that Chevy kept the small block for so many years with some minor engineering changes along the way as technology progressed. The 20 dollar investment in the book I thought was well worth it.
Bob T

THIS PAGE has 5 sites on it w/tip on 305's... Don't let anyone tell you you CAN'T build one to run. Anyone can have a 350, so why not run one of those so call "JUNK" Chevy V8's if you have one already. I put together a so-called "JUNK" 307 just because I wanted to & used tips from Fat Hack on HAMB...Joe

Michael, I have a roller cam 305 from a TPI Camaro and a 1972 vintage 350 from a Nova; one of them will go in my 58 Burb. Not sure yet which I will go with as the wife is thinking the 305 may be more economical but the 350 can really produce some torque which should allow you to keep the rpms low. Both will need some work before they are ready, the 350 is a fresh short block but needs heads and the 305 was pulled from a wreck in mid-life (~60K).

I saw some info on the NV4500 and would be interested in hearing your experience on making this swap. What parts were necessary, what rear gear did you decide on, etc.

Your best and cheapest bet would probably be to throw on a 4 barrel intake and a quadrajet from a similar sized SBC.

Your next best bet would probably be to get a pair of GM Vortech heads; but you may want to check with a machinist to determine how much to shave them to give the 305 a decent compression ratio. They're only about 500 something bucks and make terrific power.

Your stock cam is good for torque production if you want to keep the motor torquey. A slight boost in compression and better heads, intake and carb would make a very big difference. Also consider the best exhaust you can get to fit in your truck.

The 305 head has the same combustion chamber size as the old "power pack" head for the 283, 58CC. It's possible to open up the valve pockets to accept 1.94" intakes, and 1.6" exhausts, and keep the small chamber heads for decent compression with the smaller displacement engine. With a little port matching and polishing, plus flattop pistons and a 290 degree duration, .450" lift Comp cam, the little 305 really comes into its own. It's still got the long stroke, (3.48") like the 350, so low end torque is pretty good, and it will live pretty comfortably at about 7,000 RPM without overstressing anything, so long as a good set of ARP rod bolts are used. Balance it all to +/- 1/10 gram, and use about a 500 CFM carburetor and a set of 2 1/2" pipes with ram's horn manifolds. Headers are a waste of time, money, and effort, unless you intend to operate above 6,000 RPM most of the time.
Jerry

My vote is for Vortec heads and a decent cam from Summit. I ran a 305TPI for a while in a project with this combination along with stock exhaust manifolds that I port matched.

If sticking with a Carb, I have used a 390 Holley for a good street engine.

I think everyone missed out on the 'reasonably cheap' part. And since you mentioned the 2 barrel carb was bad, you wont be out much with a 4 barrel carb and intake upgrade anyways.

Jeff

Thanks for all the advice! Yeah, cheap and something I can bolt on would be best. I will go for the 4brl carb and some block hugger headers, unless the rams horns will be fine since I won't be revving up to 6,000 rpm. I wish I knew how to make a cam change, is it hard to do? As far as the carb I see recommendations for a 500cfm and a 390cfm. I would think anything over 500 would be too much for a stock 305. Is that 390 a 4brl?

Michael

On carb size, Too large - you will loose bottom end power. Too small - you will loose top end power. Try to ge the best of both worlds. IMHO 390 to 500 CFM will work for your street application.

Stock style (made in china) ram horn 2 1/2 inch manifolds from DORMAN (see link) will work pretty good for a street app. at $64 each delivered.

http://bbb-carb.com/Exhaust_Manifolds.htm

The key to any real performance build is building the engine and matching it to your vehicle weight, tranny and rear end ratios as well as vehicle use, as well as really "building" your engine (see books by David Vizard). With some minor modifications you can see some minor differences in power gain. Without proper tuning you can also see some power decrease. And then again, some minor improvments can be hard to distinguish any power increases.

If you want to see some improvments, study your vehicle and your ideas of what you want for performance out of your vehicle and spend you money wisely the first time. Bolting up parts that say perfomance is the most common mistake people make. You have bragging rights to the parts you place in your engine, but that doesn't always transfer to any bragging rights at any finish line.

I think a majority of people could make some realistic improvements with an RV cam, small 4 barrel carb (500 to 600 CFM), and some stock type 2 1/2 inch ram horn exaust manifolds or hugger headers.

If you wanted to spend some more money, go with some vortec heads. Remember that vortec heads also need other parts to make it work such as valve covers, intake manifold, plus other small parts to raise the price a couple of hundred.

Good luck with your choices.

I just put a '77 quadrajet off a 350 on my wifes 307 and thats a 650 cfm carb. If I had the time I might have spent it lookin in a junkyard for one off a 305 or similar sized SBC but it works wonders. Its a real night and day difference in driving that truck. It also gets slightly better fuel economy then the old 2 barrel as long as she keeps her foot out of it.

I drove it and it had no hesitation from full stop to any speed romping on the pedal whether loaded or empty. Plus they are fairly common and cheap since hardly anyone seems to know how to work on them. I had all the parts on hand and spent about $60 on gaskets and a carb kit.

One thing to mention as I learned the hard way, NEVER reuse the plastic float no matter how good it looks!

Let us know what you decide and how it goes!

Jeff

Thanks for all the input. I'm starting to feel better about my old 305 now. Maybe I will keep it (actually my wallet told me that). After looking at the links you all provided I think I will do the following: Get an Eldebrock Performer dual plane intake with a 500cfm carb, upgrade the distributor and coil, keep the old school look of the rams head exhaust manifold by keeping the originals or going with the Dorman. I may consider a cam for low end torque, but that would require outside help i.e. a real mechanic. Later on I can go with the Vortec heads since I won't have to pull the engine for that. If I can wrangle a NV4500 in there with its low first gear I should have a pretty nice 4x4 setup. Thanks you all rock! Michael

Good luck Michael. Let us know how it turns out.

Yes Sir,
I have a 71 307 with a 2bbl in a 57 BA. What a ride! It'll lite'em up and get 21-22 mpg hwy hand figured, with a 3spd O/D
All stock parts, just balanced. It works good.
dg

I think Mister Jerry, Hotrod lincoln has a clear vieuw on those engines. I have a similar 305ci project for my 1942 pickup and he gave me excellent advice. It's not about putting a 800cfm carb on an engine.
Thanks Jerry !