[V-8]

Originally posted by nevermind65


You must have a pretty horrendous cam to supply such little vacuum? Are you sure there isn't another problem somewhere?

Is the check valve working correctly? Have you pulled a vacuum on the booster independently to see if it holds? Is the cam degreed properly and/or initial timing set correctly?

Personally, I would look at another booster if you are determined to have power brakes instead of hooking up a vacuum pump. I had a truck with 5" of vacuum at idle and the power brakes worked fine with 4 wheel disks. I used a small diameter booster out of a 1 ton truck. Hit the pedal too hard and you would either lock them up or go through the windshield.

Yes the cam shaft is too big mech roller comp cams 240-246 and 608-614 lift. We checked every think and valve also. The problem is there is no vacuum in the idle. At the high rpms it is ok...