Thread: 283 to 327 Conversion

Tweet

I have a 283 block, suffix WA.

One site says this is a 1965 'C-10 to 35' motor.

How do I know if this is a good 327 conversion block?

Thanks - Bert

from the nastyz28.com site:

1965 WA 283 M/t - 175 2 C-10 to 35
1968 WA 307 M/t - 200 2 C-10 to 25
1969 WA 350 - - 255 4 C-20 to 35

Chevy used some suffix codes more than once. Who knows why since they have 12,167 combinations of three letter codes (omitting o,i, and q) and 529 two letter codes (deleting the same three letters). For the above example, the 68 and 69 block is easy to identify with the larger mains.

But what is a "conversion block"? Do you mean to bore out?

Do you mean to bore out?

Yes - can it safely be bored to 4 inches?

Bert

A lot of 283 blocks have been bored to 4 inches to make what was called a 301 in the old days. I have heard of some cooling problems with the bore but suspect the details include older blocks, core shift, etc. A machine shop should be able to do a sonic check on the walls to see if it is capable of taking the bore.

Then, all you need is a 327 rotating assembly to have a 327.

To sidestep cooling issues, you should have a wall thickness of at least 0.130" after boring.

Thanks, Dr Tech, couldnt remember that number to tell him.

mike in tucson

A memory moment:
In 1965 my buddy and I bought a brand new 365hp 327 short block and put it into a 55 Chevy. We couldnt afford the double-hump heads since they were $100 for the pair assembled (we had to save for at least 6 months for the heads). We put the stock 2bbl manifold on it and the 265 heads. Took it to the drag races. The inspector questioned the 265 with side motor mounts (duh) so we had to run some gas class.....rean like crap with the 265 stuff. Later, the car got real double hump heads and a 4bbl AFB (ugh). It got a hood scoop when the engine over revved one night and the fan went thru the hood. As I remember, Atlas Bucrons (sp?) were the sticky street tire back then.

mike in tucson

"Atlas Bucrons (sp?) "

Exactly right, ran ém on my V8 Lark early 60's

Thanks - I've read that SOME 283s of the same era as 327s were machined from the same block casting making them ideal for converting to 327. I thought this could be one of them being it is a 1965 casting.

Bert