If you're thinking of buying these heads look at the coolent passages on the ends of the deck. Is there a bridge dividing the holes (two holes or one). If they have one hole on each end it's not a bad thing but you'll want to put a gasket on the head to see if the chambers are in the center of the fire rings. This is to check to see if the head bolt holes are drilled in the right place. When you put the gasket on the head,are the combustion chambers of the head shifted to the left or right? If so you end up with one intake valve unshrouded and the other two more shrouded than they would have been if the holes were drilled correctly. I have these heads on my car and they work great. If I would have known the bolt holes were drilled wrong I wouldn't have bought them. I don't advise you to get them if they have this problem,however if you do get them you'll notice a substancial increace in performance.It would be extremely foolish to put these heads on your motor without port maching the intake to the heads because I think the intake ports on the intake manifold are more restrictive than the ports on the heads. If these heads are what I think they are and have the bolt holes drilled wrong the ports will be shifted as well. The spacing of the ports will be correct but one bank will be shifted toward the front of the motor and one toward the back. You'll notice this when you put the intake gasket on the motor. If you line up the gasket with the ports of one head you'll notice that the ports of the other head don't line up. Neither will the bolt holes,so you'll have to modify the gasket. If you match the ports of the intake to the ports of the heads the intake will be useless on another motor unless the heads and intake are used as a set. I don't know how many of these heads were produced but I know I have a set. I couldn't stand by and let this happen to you. Again,my motor makes big power but it would make more if it didn't have four intake valves shrouded even more than they would be originally. PS. Use factory gaskets.
