Holley red is not too small for a 350 street motor... I was running red pump on my 427 drag motor for two years but that was borderline for racing but was fine on the street. Things to look out for are under hood temps... I'm running a Holley blue with dead head regulator and have had problems boiling gas around town driving that I've been trying to mitigate with heat shield/insulating the fuel line. I'm switching to bypass regulator with return line this offseason.... I'm looking at the BG 280 for my new system. If this is mainly a street car, why change from the mechanical pump? I know racers that are still running a mech pump for their "low end" (~12s) drag cars.

-Chris