If Holley recommends 650cfm for a 383, what actual impairment to performance can there be if you have a 750cfm? If your exhaust flows enough to match your carb, it doesn't seem like it would matter.

:hail: IROC-Z

 

A 750 cfm rated carb is rated at a pressure drop of
1.5 "hg. A 383 at wide open throttle will only pull a vacuum
guage reading (pressuredrop) of about .5" hg. A 750 cfm carb, when flowed at a pressure drop of .5" hg will flow a lot less than 750 cfm,
around 550@.5" hg. A 750 cfm carb is not too big for a 383.

 

I just put an Edlebrock 800 on my 60 over 350. It's awesome. Wayyyyyyyyy better than the 600 I was running. I'm putting some vortec heads on it soon. Hoping to get low 13's.

Brad...

 

It's not to big. a 750 should be about right.

 

I currently have an Edelbrock Performer 750 carb on a 355 with a Weiand Stealth intake, double hump heads, short tube headers and a Comp cams 244/244 duration .501/.501 lift cam and it runs excellent with this carburetor. However I would reccomend getting a slightly smaller set of jets put in it than what came from Edelbrock.

 

I am about to order some smaller jets and rods. Should I get smaller primary and secondary jets? It does run a little rich.

:hail:IROC-Z