Mine ran fine with the 75 shot and stock(!) fuel pump. The kit was made to work with a stock 5.0 (or so they say at least) The stage 2 kit is just some different jets, a shim for the regulator, and an in-line fuel pump. I am still running the stock fuel pump with it by the way. The only requirement for the stage 2 kit is that you have a better clutch. I ran it anyway with stock and it lasted a while on the street. First run on the track killed it immediatly!
hoped that helped a little.
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My Mustang
91 LX Conv. 52,000 orig mi. Hurst shifter,King Cobra clutch, 3.55 grs, NOS 150 dry kit, MSD 6al, MSD timing control, malory coil, pullies, fms adj fuel reg, BBK 70mm tb, Pro-m 75mm maf, battery in trunk, JBA shorties, JBA subs, JBA strut tower brc, dynomax "super turbo" 2 1/2 exhaust, FMS billit distrib, Hotchkis lower cntrl arms, MAC Fenderwell cold air kit, off road h pipe.