I just purchased a Crate engine (383ci 450hp) and the builder recommends I use a holley street avenger 770cfm carb. He also suggested I go with mech fuel pump at about 5.5 psi max,yielding 80gph flow. When I went to buy the fuel pump at Jegs the 80gph pump said it will support up to 400hp. The problem is my motor should yield 450hp.

Question #1 Will to little flow present a potential lean condition?
Question #2 What would happen if I have too much PSI/flow?.
Question #3 What is the best way to determine the proper fuel pump?

Thank you in advance for your expertise.

-Tony

If your pushing 450 horses, you might consider the design of your fuel delivery system. Personally, I like a rear sump if possible feeding an electric with a regulator before the carb. Remember to have a big enough line size. Remember, with 450 HP, with good traction that is really going to push the fuel back on acceleration. This will cause a pressure/ volume drop off line. This is why I like this setup. If it was a 300 or 350 HP streeter then I would choose a mechanical.

Is there a formula for properly sizing a fuel pump? Would it all depend on carb size? I'm trying to stay away from expensive electric pumps. (I spent all my money on the darn engine) I'm about $1000 from finishing my engine. I'll spend the $$ if it is truely worth the $$$