283 block 265 cubes ?

this has had me wondering for a couple of years now and figured the chevy engine pros on here could give me some insight. bought an engine that came out of a 57 cameo p/u and was told that it was a 265. my buddy that builds engines was going to put ring in for me. looked at the casting number on the back and it was 3731548. my book says that it was a 57 283 block. we figured it was a 283 and not a 265. we had already pulled pistons out and were 30 over. i assumed ( yes i know the saying and its true.) 283 because of the numbers and got the rings. they were way big. ordered 265 rings and were right. none of the books i have list a 265 with that block number. have i missed something somewhere?thanks in advance.
bruce

 

according to Mortec that block could have been a 265 or a 283. i have always been told the first 283s in 1957 were bored out 265s

http://www.mortec.com/castnum.htm

 

You are talking 18 cu in difference, that's big, and your piston says .030. I never heard of taking a 265 .125 over or more to get your 283. Measure the bore, take the guesswork out of it.........good luck

 

265= 3.75x3 283= 3.875x3

 

The 57 265 blocks were 283 blocks but only had a 2 3/4" bore and same stroke as the 283 (3.00")

 

what i was meaning by my comment was he probably has a 265 that was bored .030 sometime in the past. that block could have been a 265 or a 283 from the factory. and yes , you can bore a 265 1/8" to 283...chevy did

i agree.....measure the bore accurately to see what it actually is

 

They did a lot in the late 50's, it was possable, back then ford and GM made motors with a LOT of meat think flathead....

 

hey RUSTY...if you know the engine was bored 30 over. how can 265 rings fit the pistons? unless your ordered 30 over for a 265 engine. which means you solved your own question! call me POP...or the old FART!

 

I learned something. I thought I new my motors, at least chevy, but it seems I learned something new..... a 265 + .125 over = 283. Never too old to learn, and not too proud to admit I was wrong.thanks.......

 

I've got a '56 265 bored to 283 in my shop, was first in a t bucket in the early '60s. Popups, ported power pak heads, one of my treasures.