2003 Viper ER 136"
Last year, I picked up my two new 2003 Viper ER's and decided to put a 136" ripsaw under mine. I got the rail extensions from Tracks USA so I could have the full 136" hyfax. I got the tunnel ext, hoses, covers, etc from Hartman. I ended getting the 8 tooth drivers (in case I stud it) and gears from.... I'm not going to say. The gears were wrong, and there were two different kinds of drivers, so the teeth would not line up. I paid a mechanic 2-3 hrs to figure this out pressing the old ones off, new ones on, taking them back off, and trying it all over again, etc.
Either way I ended getting new drivers from Chuch at Mountain performance. He was incredibly helpful in getting me drivers ASAP and assisting with any other questions I had. I ended up cracking the gear housing cover by having a gear in backwards, so that really took a lot of fun out of the project for the time.
The sled is great with the 136" and it took some time to get it riding right after tightening up the front straps. I'll never own another 121" again. Or should I say, I'll never buy a 121" again.