650 or 750?

[66dartman]

For my 360- building it with 12:1 KB pistons, eddy heads, cam around 240-245 at .050 on the intake and 1-5/8 primary, 2-1/2 collector headers with a rpm airgap manifold, should I use a 650 or 750 carb? Intimidator suggests a HP 950 holley, but would that be a little much for this combo? Big glitch is where the car will be run-5800'. I have heard it is easy to overdo it up here.

 

[dusterdon]

A race only (and I do mean race only) car can get away with a bigger carb to get those last few horses out of a motor. If its going to be street driven, I wouldn't go any bigger than a 750. A 650 will be too small. Not familiar dealing with altitude, but a 750 mech secondary holley 4779 is hard to beat. I found a nice barely used one on ebag last summer and put a rebuild kit in it and only have around $200 in it. New would be around $480. You can get what you want at a decent price ( I'm running it on a 383 with a .509 pocket ported heads, 3500 conv, 4.10, etc). It works much better than the 750 vacuum carb I had on it.

don

 

[383man]

Definetly the 750 of them two. Ron