I am hoping that Reggie and Eagle can give some advice on this question. I replaced the serpentine belt on my 90 Gt about 10k miles ago and I noticed the other day that the edges were becoming frayed in certain spots on the top half of the belt and there was a crack on an angle on the top side of the belt The range for the tensioner was in the center of the indicator so that appeared ok but the pully itself looked like it had a nice groove waring into the area where the belt rides. This looked like it could possibly be the factory tensioner and pully and that would mean it has 151,000 miles on it. The pully did not wobble or drag when spun. The problem bothered me enough to go and buy a new tensioner and pully from auto zone. My question is that the new part does not have a range indcator like the factory one so how do you know if the tension is correct. The only marking the new tensioner says is the number 4 with a line above and below it also they the aligning dow on the new tensioner did not fit in the hole properly when the bolt was threded through the new tensioner so I used a rat tail file to enlarge the aligning dow hole. Is this ok to do or did I ruin the bracket. Also the tensioner provides a new bolt and when I used this new bolt it would not tighten down the whole way and bottomed out on the bracket. When I backed the new bolt out it stripped one possibly two sets of threads out of the very front of the bracket. Upon closer inspection of the instruction of the new tensioner instructions it said to use there new bolt with the old nut from the old tensioner. Well guess what, The old factory tensioner does not use a nut on the end of the bolt it is a bolt through design. After spending an extra hour trying to get the tensioner to sit flat on the bracket and filing the metal to make the dow hole bigger I finally used the factory bolt and everything tightened down tight and ligned up good. The belt has some freeplay in it but not as much as the old one with the factory tensioner. I just hope that everything stays in alignment and that the plastic plastic pully on the new tensioner does not turn out to be a piece of junk. I know this is a lot of info but I hope that someone can put my mind at ease. Also would that dow hole being a little larger cause the tensioner to move from side to side in the future.