I'm thinking about trying a bigger carb just to see if it will make any difference. I currently run a 625 Road Demon and it's a real nice carb. I have talked to several people who use the Avengers and are thrilled with these!. I know a 670 would be fine but I'm really getting at is, would a 770 be too big?. I am planning to buy a 2500 stall converter and the hydraulic 268 Voodoo as my next cam but don't know when. If you guys think it will be a waste of time I'll just try the 670. Thanks
350/350 turbo
Hooker Super Comps, Performer RPM, XE262, 3:73's, posi

Does your engines power curve drop off at 5600 rpm? According to comp cam that's where the rpm ends on the XE262 cam.

If so 350 X 5600 divided by 3456 comes out to 567.12962. In that case I'd say the 570 cfm street avenger would be your better bet.

I'm not too sure about the Voodoo cam.

I'd stick with the 670 Avenger choice or buy a 3310..vacuum secondary carbs only open up to what the motor needs..remember GM used 750 CFM QJets on 305's and 307 Olds motors.

Thanks for the replys guys. Mr.4 speed- How much diference is it between your sugestion of a 3310(780cfm) and a 770 cfm Street Avenger?. Right now the 670 is probably the best bet but I was thinking the 770 could be jetted down for my current combo and be big enough later on when I go bigger with my cam. Any thoughts on this?.

A 3310 is 750 cfm and comes with #72 primary jets.
Not sure how a 770 Avenger is calibrated.

770 has 72/75 and 6.5 power valve.