Not sure if this is common knowledge or not, but the gasket between the pump and block, be it the original style diaphragm pump, or the piston pump, is the same gasket used on mopar gas fuel pumps from the 50's on up into the 90's on everything from slant sixes, small blocks and big blocks.

I checked my garbage "New" lift pump on an old small block timing case today, fit perfect, bolts line up and everything.

Small block chevy fuel pump gaskets are the same as well.

Small block chevy fuel pump gaskets are the same as well.

Well there you go, another source.

Where'd you hear that Brandon? Hahaha...;)