Ok so I have a GMC Vandura, Chevy 350 block powered and currently has the stock EFI system on it. MPG is shocking (as I expected) but then 200 horses from about 8-12mpg is just silly. So, obviously swapping the factory fanimoulds for good headers will help, butwhat about fuel delivery? Carbs or injection? How tuneable is the stock injection system? Am i better using good carbs? I'm new to V8's, spent my time on old VW'S up to now.