i'm currently running a 780 holley dual feed on my ZZ454 engine. seems like it could use a bit more carb. any recommendations? thanks john
my car is a 69 chevelle with a 4 speed and 410 gears.
I would think that a 780 CFM Holley with vacuum secondaries (and a large air cleaner) would be ideal, but the Carb itself might need to be tweaked (jets, springs, etc.) to provide the response and level of service you're looking for. The formula to figure CFM is: CFM = (RPM x CID) / 3456. Which works out to 788.19 ASSUMING a 100% efficiency (sorry, but not likely). Any larger CFM and you'll actually degrade engine performance. Is there a Dyno shop nearby? THAT might be a better investment!