hi i need some help choosing a carb i have a 355 sbc flat top pistons vortec heads 280 magnum cam headers flowmaster exuast and summit intake manifold its in a 1983 camaro with the 700r4 auto trans i was looking a a holley 750 cfm with vac sec and a holley 650 dp i was wondering which one would be better for me or if i should stick with the 600cfm vac sec that i already have and build it up a lil bit thanks

 

If it were me, I'd save your money and use what you have. You may see a few HP by switching to a 750...but it wouldn't be worth it. You could spend the $500 dollars somewhere else (Wideband O2 sensor, ditch the flowmaster muffler and insert a dynomax, etc.).

 

If you have enough stall in the converter to match the cam, a 650 DP would do nicely.