Here's a website for you.
http://www.442.com/oldsfaq/ofeng.htm#Engines First, figure out what you have. Sadly, for a while GM put Chevy 350s in the Olds. If that's what you have, it will be like any 350.
The small block was made in several sizes from 265 to 400. Some crate engines have been sold with 406 and 427 cubes.
The big block was sold in sizes from 366 to 454. Crates are available up to 572, I believe.
BOP had their own engines, which were superior to the Chevy. Usually better head design and a block with higher nickel content, which made for a longer lasting engine. Their sizes were usually close to Chevy.
