What size carb should I run?

[bloodrunner83]

I got a 79' 350 four bolt. Did a complete engine rebuild, put a .475 lift cam in the engine, flat top pistons, roller rockers, new performance valve springs, and the cylinders are punched out .40 over, edelbrock rpm aluminum intake manifold. Im running a edelbrock performer 600 cfm with manual choke. Some people say I should run a 750 double pumper on it and some say 600 is perfect. Let me know what you guys think please!

 

[84k20]

The double pumper will usually cause hesitation off idle especially when the secondarys open it usually bogs.... I just had a complete 383 built and had the engine shop test my edlebrock 1406 (600cfm) against a demon 850cfm and holley double pumper 750 he said he was amazed at how the edlebrock out preformed the other two by a huge amount throttle response was great.....I'd stick with a 600cfm-650 and vacuum secondary carb (either quadrajet or edlebrock 1406)

 

[woodsrider250]

That demon would be good for 600hp or better

 

[bloodrunner83]

The double pumper will usually cause hesitation off idle especially when the secondarys open it usually bogs.... I just had a complete 383 built and had the engine shop test my edlebrock 1406 (600cfm) against a demon 850cfm and holley double pumper 750 he said he was amazed at how the edlebrock out preformed the other two by a huge amount throttle response was great.....I'd stick with a 600cfm-650 and vacuum secondary carb (either quadrajet or edlebrock 1406)

Very cool that you tested it! I assume that my engine is putting out about 350 to 365 hp based upon similar engines. My truck will be mostly a pavement princess after shes done for the first year or 2 so the throttle response is gonna be more important to me. I may go bigger on the cam and carb when I start entering the stock class truck pulls back home.