I know that most everyone on here runs 88 and under but I have a 92 5.0 T-Bird and have a bad smog pump.
I found that a 855K6 Duralast belt 1/2" larger or smaller will work too. I dont know as of yet what will fit for keeping the a/c. I will find out the size of it once warmer weather comes back.
~Rich
in addition, you can also remove the idler pully, grind off a 1/4'' on the stop where the pully lever hits. that also gives you a wider range of belt sizes.
Well on my 92 the top bolt on the altenator would rub if not for the idler pulley off-setting the belt.
~Rich