Here is my pulley setup and what I had to do to get it to work, for those who are reading this thread needing a belt size and have a similar setup to me.
MAC underdrive Crank pulley
MAC underdrive water pump pulley
Stock 3G alt pulley
Stock PS pulley
Running the FMS AC delete kit
No Smog pump
I was having rubbing problems between the water pump pulley and the tensioner. When I installed the 70.5" belt, the clearance was there at first, but once I ran the engine for a little bit, they started rubbing.
What I had to do was this:
Grind the hole in the tensioner mounting bracket where the nub goes into. I had to grind it counterclockwise about a half an inch so the tensioner would rotate counterclockwise a little more. Then I had to loosen the 2 power steering pump bolts and remove the top one so the pump would rotate enough for me to slip on the belt. Once the belt was on, I just pryed the PS pump back into place (is it was rotating on the lower of the two bolts) and put the top bolt back in. The belt I ended up using was a 69.5 part number, so I'm guessing it was a 69.5" belt. Might want to note that this was a Duralast brand belt. The nice thing is that the clearance is about a half an inch now and the tensioner is perfectly within the 'range' of tension that it needs.