We just picked up a Sc3 skid from a fellow TY member, (thanks). We can not wait to install in the Viper. The Viper is a 136 track, the skid is a 121. We are going to relocate the skid back 4" and extend the skid 3.5". This should give us a much better approch angle and proper geometry for the skid/track. Any suggestions??? Al