OK the tap it is, and thanks to badsport, he was the first to offer the same fix as you all have said, the heads are not on now,i am sure it can be done after the heads are on.
You wrote, "i am sure it can be done after the heads are on.". If you do the tapping with the heads on the engine and the engine in the car it will be more difficult. If the heads are on the engine and the engine is "out" of the car then it's pretty easy. Which scenario are we working with here??
Treblig