I can buy a complete 350 motor from a 1980 truck, it is a 4 bolt main and it needs to be rebuilt. I can get it for $100. What i need to know is that can i use the block to build a 302, and would i be able to use the stock heads. And the last question is what do i need to build this 302.
THANKS MIKE

 

Yes you will need a 3.00 inch stroke crank.

 

Well, you could get aftermarket crank from Lunati to get the 302. I seriously doubt you will find a Z28 large journal 302 crank to fit the block.

 

So i can use the stock 350 block, but i just have to find a different crank, How much is a aftermarket crank.

 

Go to your loacal newstand and pick up the new issue of hot rod(august 2002). It has a pretty good article about what it takes to build odd displacement engines from stock small block parts. If you could find a 307 crank(68-73) it's the same as a large journal 327, but I think it's a cast crank. I'm pretty sure you can pick up aftermarket cranks for a 327 large journal crank for a good price as these engines are still pretty popular.

 

unless you're limited by class rules why would you want to make a 302? it has 48 cubic inches less potential than the 350 you're starting with.

 

because it has a nice short stroke that you can rev with.............................

 

you can take the same parts on a 350 and make more power and you won't need a 1000 dollar crank from lunati. it's not that i don't like unique set up, hell both my carmaros are sort of bastards.

 

This would give him a 327 not a 302. It's easier to build a 302 with a small journal 327 block than the large journal 350. If a small journal block is used then all you need is a 283 crank and a set of 302 pistons. Then have the assembly balanced.

 

The limiting factor will be the valvetrain not the stroke.
A 350 with the same valvetrain will buzz just as high.

Onless you have a close ratio 5 or 6 speed trans and a high gear ratio
the 350 will be faster given the same mods and budget.

This is going to cost you a fortune and you're going to be disapointed.

 

The redline of an engine is more dependent on the valvetrain and heads, not a 1/2" difference in a crank.

 

chevymad is right about that crank. My bad but it is possible to use a 267 crank with a 3.100 stroke to get close but I think ultimately you'd be better off the go with a 327 or 350. Just my opinion.

 

Would it be better maybe to use a 327 block instead.

 

except for 68 blocks all 327s will be sj cranks, but if you find a sj 327 bolck use a 283 crank and you'll be all set

 

Let's not forget that you have to use pistons appropriate for the stroke. 302, 327, and 350's may all have the same bore, but the wrist pin location is different, making each one unique.

FWIW, the 302 I had back in the mid-70's was a SJ 327 block with a 283 crank (they were all steel, by the way). .060"-over, 12.5:1 compression, LT-1 heads & solid lifter cam, Torker intake...

 

Or you could just leave all those engines for the collectors/restorers and get yourself a 350/400 from a 70's truck and forget about the 302 all together......

 

The compression with that truck motor is already down around 8½:1; with those crap heads, it may dip down into the 7s if you take out cubic inches like that...

You need heads with 58cc chambers or less, and you need them to flow big-time just to stay even with a 350 (which of course will go faster with the same set of heads). And you'll need to either outbid somebody trying to restore a 68 or 69 Z28 to get one of the about 2 or 3 Chevrolet large-journal 302 cranks remaining on the face of the planet, or shell out mega$$$$ on an aftermarket 3" stroke crank.

Build the 350, and get a set of decent heads. The 350 will beat an otherwise identical 302, every single time. Why spend extra money to hurt your project? This business of destroking something to get a supposedly high-RPM motor doesn't work. I don't suppose you're old enough to remember; but some of us stopped bothering with building 302s and 327s the minute the 350 became widely and cheaply available, because the smaller motors lost races!!!! You can do what you want to, but if you downgrade your 350, I hope I run across you on the street in a race someday because I will drill you.

 

So if you wanted to build a 350 that could rev like a 302, what would you need?

- solid lifters (roller?)
- big duration cam

A web page said the 302 cam was 227/237 @ .050, with 78* overlap. I'm not sure how that translates to LCA.

- roller rockers?
- forged crank?

 

with the same parts any engine will rev the same doesn't matter what the cid is

 

if you want a 302 and not spend $1000 or whatever on a specialty crank you'd need a small journal 327 block (older than around '68) and a 283 crank OR a 1 piece rear main seal 350 block and a L99 crank. Its the 4.3L v8 from the B-body Caprice.

 

I thought it was the new Vortec 4.8's outta the trucks that used the 3" crank?

 

That's a LS1 derived engine (Gen 3) and 100% different than the Gen 1 (pre-LT1 design) and Gen 2 engines(LT1/LT4/L99).

 

Yup you're right it is an LS1 based engine. Forgot that for a sec there.

 

ya but if you wanted to make a 302 LS1, that's the crank they've been using along with a bore-over. Its like 3.10" or somethign though. its a bit off the original 302's 3"

 

Ok, i have been looking at rebuild kits and i guess that i will stay with the 350 and try to get around 300 or more horsepower. I know that i will always be faster going with a 350 but i just thought it would be cool to have a rare engine, i guess i will have to wait a while.
THANKS

 

whats wrong with trying to build a nice 327? 3.25" cranks are much easier to find and i would think the small loss in cubes could be easily outweighed by revs granted you have the right gearing and valvetrain.... I thought about making a freak 327 LT1 for my car..seeing how I already have heads 2.02/1.60 and valvetrain..can you say 7-8 grand shifts all day

 

What a 302 is: a Chevy small block with a 283 crank and 283 rods. I think it would have 350 pistons, I don't know what cam/lifters. I have never seen a 302 beaten. I have seen them eat big blocks. Build it, it'll be cool - it won't be cheap, but it'll be cool. And don't put a 327 crank in it, a 327 cam maybe, but not the crank.