[olddog]

Jac Mac,

The bolts are correct and the taps I used - 5/16 - 18.

The other eight holes, I can spin the bolts and the taps down with my fingers, with ease.

I agree something was wrong with these four holes. I suspect they were not right from the day they were new, as it is suspicious that it is the 2nd hole from the end both sides on both heads. A pattern makes me think a manufacturing problem, but since I have no history to back it up, I may be flat wrong.

I would guess the heli-coils are lock tight or other wise glued in. I'm concerned on how to get them out. Should I heat a bolt with a torch to loosen the glue before trying to get them loose? With out at IR gun to monitor the temp, I'm worried about the aluminum.