need help iding 6

I need help iding these 2 straight sixes that once both owned by Tommy Schonsberg. I seem to be picking up a few of Tommy's cast-offs as he had also at one time planned to race the 68 Cuda ragtop that I now own. He rebuilt the black block and never used it as he decided to go a different route. I'm not sure about the history of the blue block. The black block is numbered 4343-730 and dated 19-1-87. The other side of the block shows 220. The blue block has 10015 and 2463430-15 on one side and 652 on the other. I couldn't find a date.