No special single four barrels were ever used as a factory super stock. As was said, in the 70s there were Direct Connection part numbers (all begin with "P") on a few Edelbrock intakes. The aluminum 6bbls were 69 1/2 and I think a few 70s, but not Super Stock. They were just the std 6bbl intakes and when they ran out, Chrysler cast them out of iron for 70-71. The 6bbls have astd chrysler part number, not a P number.