I also run 20" haulers. I ran it with the mods listed below and stock gearing. I thought it ran great. Then, for the hell of it, I tried a 16t front. I couldn't believe the difference. My motor really comes on in the mid range and the gearing lets it really stretch it's legs. Ya, it hurt the bottom a tad, but just keep the revs up and it's no problem at all. Shooting up really steep hills is no problem in second gear.