Has the bottom of your head, or the deck of the block ever been planed? E.g. from warpage etc? This is common during a rebuild.
If so, the crank-to-cam distamce is shorter than stock.

It also is possible (although unlikely) that little oil pressure-driven tensioner on the TC is stuck "in" orjust not working, when you took it apart the 2nd time did you check to make sure it was springy?

With 200+ Billion electrical parts, the world most complicated machine is inside your own skull.

Question Reality.
-----------------------------
'89 Rnr DLX "SR4.5", 32s w/ 5.29 locked f/r blah blah