LS-7 Crate Engine

[Yellow 69 z28]

Does anyone know what years did the LS-7 crate motors run from - to? How about L-88's? Would GM have used a 14015445? Does anyone know what the GM part number would of been for either the LS-7 or L-88? Would the short blocks have been painted?

Found a brand new GM short block with pistons having a casting number "3947886 GM" stamped on the top. The block is not painted or stamped but has unusual multi-color paint markings all over on the block, crank, and rotating assembly. There is a cam present, but I have not pulled it yet to view the p/n. I also need to look at the crank p/n.

Just curious.