COMMON SMALL-BLOCK OLDS BLOCKS
One easy way to ID Olds engine displacements is by the block casting numbers and ID numbers. We’ve listed mid-1970s-and-later 307-and-larger small-block Olds V8 cylinder-blocks in this table. 330s were only made in the 1960s and today are very rare. 260 numbers aren’t listed because no one cares. Both ID and casting Nos. must match; ID digits may have been used more than once for other displacements. Desirable “solid main web blocks” have full-thickness main webs for added strength.