Hello, To answer your question. I have the kongs mounted on Titan twin rims and used the Titan twin hex hubs. The Cen hex hubs are 19mm and the Titans are 21mm. I drilled the Titan hex hubs to accept the Cen hex pin as this pin is bigger. Once the kongs are mounted on the Titan twin rims and the Titan hex hubs are on use blue loc tite on the wheel nut and check the wheel nut after every run, it will stay tight after about 2-3 tanks, if it comes loose it will cause damage to the rim hex mount. This set up will make your Genesis about 4" wider and I had to adjust 3rd gear shifts but this thing still pulls the wheels off the ground and hauls U know what. The only other mod was I made a front end steering stabilizer to keep the front wheels from shaking at high speeds. Also I ran it this winter in 4-6" of snow and it was a blast and will not stop, just be very careful when in the deep snow, it will freeze up the brakes and when you hit the brakes and nothing happens stuff will break, lots of stuff LOL.