The reason I ask is, one day when I have the money I want to build a dual purpose rig. I have seen a Jeep on 52" tires that had a decent amount of flex (at least more than the other mud trucks I've seen). He kicked ass in the mud but I can't see him doing too good on the rocks. I also see a lot of rock crawlers running 2.5 ton axles and 350 crate motors. The problem i see for them in the mud would be, they have a lot of moving parts to get the articulation they need, and they are geared extremely low(not much for speed). I think it would be cool as hell to have a rig that could do both good. Maybe not great, but could hold their on.:smokin:

Probably the XRRA rock race guys would be the closest to finding that middle ground. They've changed to more modest gearing and WAY more horsepower. Slap on some mud tires and they should be "decent" in the slop.

A leaf sprung rig should work well. Run high gears in the axle and stack the t-case to pick your range. The high axel gears and high range in the t-case should give you more wheel speed for mud and drop the t-case into double low for rocks.

it wouldnt be hard to do. run a couple transer cases or a black box. then run what ever tire you want when you need the gearing throw it in low or double low or what ever you want on the rocks then put it in high when you need more speed hell most the mud trucks in florida are running at least 2 if not some times 3 transfer cases they got it when they need it cause they do alot of tug o war

Grumpy Old Fart has pictures of his rig flexing out pretty good as well as running mud. Good suspension travel is important in a straight line mud race just as much as going up rocks. You don't need a well built suspension to go fast in mud, but you will be faster with one. As for gearing...just run duals to get you compound low for the rocks and run the mud in single low. My Toyota does ok in both rocks and mud, but not exceptional in either.