Small Engines (Lawn Mowers, etc.): I need to know the length of deckbelt on lawntractor, lawntractor, lowe s

Question
I have a 2004 model troybilt-17&1/2 hp. 42 inch deck lawntractor model #13AN689G766-serial number 1J124H10495. Today the deck belt burned into from heavy grass. I had bought a spare belt from Lowe's but apparently someone had put the wrong belt in the belt box. It was 5/8 X 69 inches long but was to short.  I bought a 5/8 X 74 inch which was way to long. At walmart I bought a MTD a belt that had the same numbers as the orginal but it was way to long also. So, I'm kinda at my wits end. I can get a less expensive belt than the MTD brand if I know how long it is supposed to be. My manual does not give the length of the belt. If you could supply this information, I would sincerely appreciate it. A friend that put the last belt on is trying to put this new one on. Could something have happened to the deck underneath? He only removed a few clip pins like last time and tried the above mention belts. Thanks again, Stephen

Answer
You pretty much need to use either MTD belts or an aftermarket belt from Stens, Rotary or Oregon.  Other belts won't have the proper angle and won't fit properly.  The part number is 754-0371A, I don't have the length.  I don't want ot point this out, but you seem to have spent extra money and time in not buying the MTD belt from a parts supplier or shop in the first place.  

As long as everything is hooked up and there's tension on the belt, you almost can't put the deck back on wrong.  Thanks, PK.