how fast
 

i found a deal on a ford 302 gt-40 long block with alumnum heads with a b303 cam its rated at 345 hp what could i expect in my 91 gt with basic mods and 373 gears for 1/4 mile time etc, saying i stay with my stock intake and injectors for now until i upgrade.

With stock intake, maf and tb i'd say 250-260rwhp get a gt40 intake bigger tb and maf and you should see 270-280rwhp.