max wedge blocks had TMP stamped with a large font on deck pad on a 62 dated block.
then there was a VMP stamped on a 63 and 64 cast block. also had a 426MP stamped on pad as well.
also you;ll see a AAQA on front of the block.street wedges also had AAQA.
also theres a notch for valve relief at top of cylinder to accept larger Max Wedge exhaust valve.