I have one of the original kits. I was preparing it to sell and as I was going through it I couldn't help remembering the last few times I ran it. It was getting dialed on the big tracks. So I decided to keep it. I have all sorts of tires. I upgraded the base kit with the FT upgrade kit(VTS, Brace, steering rack), RPM Arms, STRC pullies, Sway bars, FT Wheel hexes, C-Hub mode, and finally a mod for dual Shorty packs.