My Viper had a mono from a '06 Attak in it. I replaced it with a newer 136" mono from an '08 Apex and used the Apex brackets as well. Pretty sure most all the hardware was the same from the Attak to Apex, at least I couldn't tell the diference. But the only thing that really did change was the overall location of the skid and rear upper idler shaft. I also added TracksUSA rail extensions to go 144". Wouldn't have it any other way quite frankly. Next I'm going to change out front drivers to extros, then big wheel the rear idlers to 9". Currently running a 144x15x1.6 cobra track and am loving it! One last detail is I'm going to increase the upper rear idler size from 5.25" to something closer to 6" as this will raise the track off the rear arm slides, which keep the track off the shock eye. Track is barely touching those slides now cuz I run a really loose track, but I just want to eliminate friction points.