Fuel system help

[Italia's 67]

Hey guys,

Ok I've been doing a bunch of searching and I can't seem to find a good way to go about this. Maybe some one on here has done this correctly.

I picked up a 99 vortec engine for my 67 c20. There isn't provisions for a mechanical pump as I'm sure you are aware. I have a Holley style rotary vane pump and a Mallory return regulator. This is a carburetor setup.

My problem is trying to figure out a efficient way to run a return line. I found a replacement behind the seat tank through LMC that has a 1/4 bung somewhere on the tank. I tried to ask them the location but they had no clue. My concerns with this tank are:

#1 is it too hard on a frame mounted Holley rotary vane style pump to use the stock style pick up

#2 is a 1/4 inch bung too restrictive for a pump that flows 105 GPH at 14 psi?

I really like the idea of the behind the seat tank but if it's just not possible I'm open to suggestion that don't involve $400 aluminum tank at the moment.