[rfox]

I have a Heavily modified 289,+030 w/pop-up pistons,ported 351 heads w oversize valves,Isky [email protected] cam,rhodes lifters,torker intake,headers,2.5"duals, 5speed, 4.11s, 6500 max rpm. 4777 650 double pump. [no choke]
Ive seen ads for those proform replacement main bodies [+25-50 hp] and
am wondering if since I really dont need any more cfm would this be a waste of $$. thanks,


Bob
67 Mercury Comet

 

[arnoldtx]

If you really got that extra HP it would be worth it.

 

[Hottarod]

Carburetor Main Body For use with Holley®650 CFM (Flows up to 690 CFM)

The 650 Proform main body is a nice design with screw in bleeds and down leg boosters and supposedly provides a real 690 cfm air flow. The out of the box Holley 650 may flow 625 or so.

I opted to send my 650 off to a customizer and have it worked. I mainly needed 4 corner idles but he went ahead and flowed it out to 690 which I can use. He checked for square and true, fixed a couple of helicoils, fixed one fuel leak I had and essentially blue printed it. My car doesn't run a whole lot faster but it does crank up and idle a lot better with no idle hunting. It has much less tendency to try and stumble or catch on fire too which is always a good thing. It ran ok for several years before having all this done. It was either this or buy a whole new carb.

Hard to say on your set up. It will either run the same, run slower or run faster, LOL. I think that has it covered.