You didn't tell us about the combo.
Intake?
Gears?
Car?
Tranny?
Exhaust? (Headers or not)
Cam? (Stock or not, and what year engine if stock)
From your general post, the safe answer (good for just about any street combo) would be a 3310 Holley with the electric choke and Ford kickdown options.
Remember also that a good Holley 'super-tuning' guide is manditory no matter what! Read it over and over till you 'get it'.
Good luck
Dave
Also depends on what intake manifold he has, his may have the stock spread bore intake. Also recommend a 750 Holley VS if it's an automatic car, but change the secondary spring to a lighter one. It's been my experience that the choke on Holley's are useless in warm climates. I've ditched every one I've had, removed them completely.