Chris is correct. it is psyical size. although one company of the V8's didnt have a "small" or "big" block and that was Pontiac. they all utilized the same block structure. Olds so called had a "small" and a "big" block, but mainly they just raised the deck height. the psyical size of a Olds 350 compared to a 455 Olds isnt that much different. just thought i would throw that in
