shogun,
it depends whether you are running carb or efi as to the style pump you are running. Mechanical pumps are going to give you about 6-8 psi. Most aftermarket electric pumps mounted externally run the same 6-8 psi and both of these work great for a carb set up. If you are going efi, those systems require around 40psi which is the "in tank" style found in fox body stang...
What are your plans for this project?
LB