|my head as big double checks are:
1.) When you remove the tensioner, be careful about putting the tensioner bolt back in and compressing the tensioner. If done too quickly, can crack the casting of the tensioner assembly. Can also do it in a vice when off the car, which I believe is a safer bet.
2.) Inspect the tensioner carefully for damage/condition.
3.) After you have the belt installed and tensioned. Do a bunch of rotations and a few checks on the tensioner gap to make sure it doesn't change. Some people even let it sit overnight and check the next day. Not a bad idea, if you have the time.
I like to use the Z32 wiki as a double check of the procedures as well as the FSM.