just bought a 69 olds 442 convertible with 455 engine, seller said this was not the orginal engine, can anybody tell me how to find out about this engine? the number that i see in the block is 396021 thanks JO
F '68 - '70 455 396021 Common big block. Stick type F (sans serif).
F '70 - '72 455 396021 Common big block. Serif type F. Two vertical
and a base serif.
Fa '72 - '76 455 396021 Very common big block. Marine also (L VIN derivative
Also found this info, dunno if it`s correct:
The 396021 block casting number was used on 455's for their whole run in passenger cars from 1968-76.
If you're buying a long block, the letter on the corner of the heads would be your first clue to the year.
1968-69 455 would commonly have the C heads, 1970 the E, 1971 G, 1972 G(small A), and 1973-1976 the J heads. C, E, G, & Ga all flow about the same; J's less but they can be improved with porting. Chamber sizes are also similar on all these heads.
If you find a 455 with D, F, or H heads, just buy it an don't act excited till you get out of the yard.