Erratic Vaccum Reading

I can't add anythign except "New dont mean good". Every set of heads from any aftermarket source get sent to my machinist to be checked and corrected. The equipment he uses is state of teh art, and it makes the heads better than assembly line slammed together... Which "out of the box" they are. I've found wrong springs, valves with marginal angles, locks not in properly, seats out of round, and at least 5 out of 16 guides are too tight for my taste. Plus, you can elongate the pushrod holes while they are apart. If you spend $2K on heads, another $400 is cheap insurance, more power, and longer life.