Motion Replacement Engines

[RichSchmidt]

Motion usually started their big block builds with GM crate engines. I believe the last year for the 512 block was 1971 and it was used in both high performance 427's and 454'. I believe that all 72 and later 427 and 454 engines used the same #289 thick wall block which was also used in some 1 ton trucks and high performance cars in that year. Basically both blocks are thick wall,high nickle content blocks,and are the ones most often regarded as being able to be bored 1/8" over with no block filler.