got some tires for my MCD Ultimate monster truck and the rims are too thick. Cant put the nut on. I eventually did fix it by drilling out the axle hole a bit deeper. Anyhow i found as i'm shopping for tires, most places say that "these will fit, FG trucks, Rampage, MCD....and so on. Obviously at least one of them has longer axles. Can anyone tell me which is different from which? thanks