I just rebuilt my Pontiac 350. Vacuum is low at 15. Power sucks. Engine wants 15 degrees of ignition advance at idle. I installed my 260H cam straight up, dot to dot. It seems crazy to me that I could have installed it a tooth off. Here's how I am checking the cam timing: I am checking the intake opening; cam card says that the intake valve opens at 24 degrees before top dead center. I can eyeball that. So I got my dial gauge out, put it on the pushrod side of the rocker arm and turned the motor over until I saw movement. I look down and the little white line on the balancer is about 24 degrees before top dead center. If I was a tooth retarded I figure that the valve would open somewhere around 8 degrees before TDC. However, I know that the cam runs at half the speed of the crank. Are the cam card's numbers for Crank 360? or do I have to multiply by two? I think I installed my cam right, but I'm not sure about my checking methodology.
15 degree initiall advance is not bad. I usually shoot for 18-20 with a total around 36-38 on an open chamber head. And 15-16 inches of vacuum is normal. If you said that hat the engine needed 40-50 degrees of timing to even to run I would say it's a tooth off. Dial in the cam by using the intake centerline it's more accurate.
