Can a 307 be bored 4 inches and use stock 350 pistons and crank? I have some stock 350 parts laying around and a stock 307 engine that I was thinking of convering into a 350. Any info would be great.

Thanks

There has been some that said this is possible and they`ve did it.
The only true way to know if it will would be to have the bores sonic checked. This procedure tells the thickness of the walls and how much overbore they can stand. but it`s not cheap, and in the end your better off finding a 350 block to start with.

68-71 block probably, 72-73 block is thin walled and is a maybe .125 on these is asking a lot. But given the billions of 327/350 blocks out there, I'd just pick one up and be safe.

Bogie

307 blocks with casting# 3970020 i know for a fact they can be bored out to 4.060. my cousin did it once to make a 327.

Cylinder wall thickness needs to be minimum 0.135" after finish honing, so if the walls beep 0.1975" before you start, you'll be o.k.

i guess making a 307 into a 350 wouldn't be cost effective. how about a 307 into a 327? What is required to do this job?

A 307 uses a 3.25" crank so boring it out to 4.00" would give you a 327. 327s and 350s have the same bore but different strokes. In order to get a 350 from a 307 you'd have to bore it to 4.00" then install a 350 crank which would be pointless and would get you nowhere except a bigger hole in the pocketbook.

If you want a 350 then find a 350. If you want a 327 then find a 350 and steal the crank from the 307.

if u really want to do the motor up, just build the 307, thats wat i did to be different and all, i have about $6000 in mine and it is pushing over 350 horses not bad considering stock was only 126 with a 2 barrel!! lol if u need some ideas let me know, i put mine in a 69 chevy c10 and it hauls for a 307, better than a 305. my opinion.

Or you could spend $6000 on a 383 or and get 450hp (or more) and be faster than anybody else with a 350hp 307, 327, 350... But, whatever floats your boat...


Yes I know this thread is old....

yea thats true, but im only 16 and this is my first truck that i built and that plenty of power for me!! lol but u are correct, but if someone wanted to keep the car number matched and still wanted horsepower you could do it... my truck came with the 307, so if i ever sold it the numbers match right up...