No don't need it , just use a pump without the return line. Somewhere in the 70's I think is when that style showed up. Looked so weird rusty and flipped over I couldn't recognise it, hehehe !! .
Funny! I actually conversed with Carl S on this topic recently... The first fuel return line I have seen on a full size Pontiac is on my '68 Strato Chief RCMP car that had a 396ci.
This will work out fine as I am tempting EFI in this one as well.... All of my other ones didn't have the line and I had to run them....