LS6 block
 

I have a original LS6 block and heads. About ten years ago I had to get it decked, before I knew what it was worth. You can barely make out the numbers on the pad. TO4?? i believe it ends in CRR. The very last letter definetly is a R.You can see the top of the C and very top of the second R. Is there another way to verify the block(3963512)? it is dated C23 70 and the heads are dated C6 70 and d13/70 (3964291).
Doug