Hey Rockit - After all your measurements and different head, etc, the only other thing I can imagine, is perhaps a "lemon" head (unless you've tried a few). I've heard that can happen, but never experienced it. I would be interested in seeing a pic of where the wrap meets the bearing edge area.

Again, good luck.

B

A couple things come to mind:

Some heads won't seat on certain shells at low tension. I had some remo heads that would not conform to bearing edges. Replaced with other heads, bingo.

The edges may not be level Put the shell edge down on a very flat surface. (plate glass is good). can you see any unlevel areas of the edge?

Also, I had a Gretsch tom with bent die cast hoops. Tried to re-bend them into flat and round, but didn't work out and I ended up tossing them. New hoops cured the problem.

And the 5 lug toms are a little tricky to get used to tuning.