We've got a guy up here running a Cobra with 5L engine out of a 2000ish GT.
He has fitted trickflow heads, inlet manifold etc etc.
He is just using VL Commodore fuel pump. Works perfectly. Apparently the 6cyl, v8's & turbo's ran the same pump. Well that's what the wreckers claim. I would check this though. His is just a 6cyl pump.
Cobra ran 12.7 1/4 mile the other day, so definitely no problems with fuel.
This could be a good, cheap way to go, until you decide to stroke, turbo or supercharge it.