What size holley for 350?

 

Depends all on the vehicle and what you intend for it, If its been modified (headers, intake manifold, compression ratio, cam and so forth) you could use a 650-750 to 850 CFM , if you've modified it like that

Likely a 600-650 CFM would work fine. If its pretty stock then a 450-500-600 CFM Holley should work fine, Have to make sure that you have the kick-down style if you have an automatic. The Holley 4160 is nice and you can find one that will meet FED and CA emissions regulations too.