date code info here:
Holley Carb Hunter's Guide
The 93 day of 1979 and the 63 day of either 1974 or 1984.
The slash cut vent tubes is probably the newer one.
Blocks: I have one -2 with its original primary block. Made the 128 day of 1976.
It has both the block number and the carb list number.
View attachment 1715995122
Here's what it looks like.
It has kill bleeds in the angle passage and idle restriction at the bottom of the well (best location usually)
View attachment 1715995130
Mapping out the block and its associated air bleeds.
View attachment 1715995129
The PV wasn't stamped but acts like an 8.5
Factory PMJ was 72.
The secondary block is a 6497 off of a 4777.