Going through friends 528 Wedge with CNC ported Indy heads. He bought it complete a couple of years ago from states, and it really hasn't performed according to expectations. I'll tear it a part and check it, and while at it he wants to install avacuum pump since the engine was designed to use one. What all is needed, and where to get the parts from? As far as I've understood,you aim at certain vacuum and limit it with aomekind of a leak retriction? Any good links or articles?l