Fuel Line:
Up to 250HP = 5/16" or -04 AN
Up to 375HP = 3/8" or -06 AN
Up to 550HP = 1/2" or -08 AN
Up to 800HP = 5/8" or -10 AN
Up to 1200HP = 3/4" or -12 AN

Injector Size:
The general rule of thumb is that it takes about .5 pounds of fuel to make 1 HP for a naturally aspirated motor and .6 pounds for a Turbo motor