69 firebird exhaust
Hi, me and my son are re-doing a 69 fbird. It has a 400, 4 spd and prior to us working on it had lots of lame brained repairs, ie coffee cans in places coffee cans don't go, nails for cotter pins, that sort of stuff. Anyway, basically the engine has been totally redone. Other than a magnum roller and I think 280 split cam, its .30 over stock and has edelbrok intake and 750cfm edelbrock carb. The question is re: exhaust. I bought some hooker headers and plan to put either 2.5 or 3" pipes to flowmasters on. I don't understand why one would be better than the other, I mean the old american way, if one is good, 2's gotta be better, why stop at 3"? Can anyone help me understand the nuts and bolts of how to select the best exhaust for this car? Its not going to the strip, or even to the blvd. Just to school, dates, and errands for me (I'm sure thats all my son will admit to anyway), thanks!