Which Fuel Pump?

The Carter M6866 that Oldmanrick linked to is a stock style pump and has a max pressure spec from 5-6.5 psi.

The MP p4007040 that the OP first looked at is a Carter M6270 with a cutoff spec of 7.5 psi. Ryan Brown tested one and confirmed and pressure goes to 7.5 psi. Graph and table of small block mechanical fuel pumps on my website here