replacement blocks

[yountto]

"In other words you WILL NOT find a CTB coded 70 LT1 over the counter engine that was assembled after August of 1970, as there were none made after that with that code"................. Mark, How then do you explain the "CRR" stamped Ls6 coded 1972 1973 and later vintage Ls6 OTC motors???..They were built years after the 1970 Factory Ls6s..... I have 3 of them here and they were even built using #289 casting blocks as well as #512..build dates and CRR are stamped on the front pad....NO vins obviously.....I believe this was done because there werent any ls6/ls7 motors in 1971 production to change to another build code,hence CRR stayed for years after 1970 production on over the counter Ls6 motors......