I have run a NA Apex for several seasons. So far I have done Timbersled front and rear suspension (which I would recommend, just make sure the front end fits tight when assembling), Hartman clutching, and CE -162 track. I have also done an Excell under tunnel exhaust and Boss seat. I would recommend doing suspension to save weight and improve traction/weight transfer. The track was a significant improvement over stock, as well. If I were to do exhaust/seat, I would go with a Skinz seat/exhaust combo. I had some problems with the undertunnel exhaust choking in powder until I made shielding for it. The sled works wonders when climbing at a slight angle. It seems to go forever when going up at a slight angle. Straight up, it can slow easy, but at a slight angle it works very well, and can impress/embarrass others.