I'm trying to select a right size carburetor for my engine, it's a refreshed 350, Lunati voodoo cam Duration @ .050 (Int/Exh): 213/219 , Gross Valve Lift (Int/Exh): .485/.499, Comp cam magnum roller rocker arms, lunati valve springs, perfomer manifold, hooker headers, msd ignition, true double roller timing chain,

I have street avenger 570cfm. With manifold and headers only it ran fine, but after the rebuild it would surge at part throttle and high rpm, and backfire through the carb.
I was thinking about 670cfm or 770cfm setup for small block.
Please help.

 

650 or a 750 with be a nice carb size to get

 

I really like Street Avenger series so my choices are limited to 670 or 770.
I had Edelbrock 600 with stock setup and replaced it with holley street avenger 570(my buddy bought it for his mustang project) and noticed the difference. Street avenger was a lot quicker and much more responsive on my car.

 

OK either choice is good IMO.

I would go with the 770 though

 

I have a 670 Street Avenger on a similar build. 355 at 9 to 1, 210/216 Engle cam, best ET comes with 68/73 jets and 36 degrees total timing.

 

Do you guys think 770 would be too much???
I'm ordering a carb on Monday and I just can't figure it out, 670 or 770cfm.



Please help

 

IMO, the 670 will be fine for that application.

 

Thanks Jim, I was leaning towards 670cfm, I just needed little reassurance.

 

id say 670. i have a 770 on my 70' 355cid. works great, but i also have edelbrock performer rpm heads and intake, with a .523" lift, 236deg cam, headers.... if your in doubt, go to holley.com, and in the upper right hand corner, there is a carburator selector program. just put in the info you want/have for your car and it will give you the ideal options for carbs. theres even a mathematical equasion for perfect world circumstances which you normally add a few cfm on to. its max engine rpm x cid, then divide by 3456 and thats your ideal cfm in a perfect world. or just call the holley tech guys, and they will let you know. if the holley dosent run as good as the edelbrock, its because theres more to tune, and when thats done, its a better carb hands down.