TowRig.com - Diesel Discussion and Tow Tech

Have an '05 Ford F550 4x4 that we use around the farm hauling bales and as a delivery/tow rig for our seed business. Winter driving is primarily off road in mud , snow, ice, etc.. It gets around much better off road when the rear is singled out. Currently running 225/70R19.5 Goodyear G124's whic do OK, but really need something more agressive.

Any 19.5" tires that are Load Range F, G, or H that are more agressive than the G124's, and speed rated at least 75mph?

Plan to have a custom single rear wheel built, so that it tracks properly with the front.
To open up my tire options, I would consider another rim size/width, as long as I could match tire diameter to the 225/70R19.5's.

Am currently running Goodyear G124's 225/70R19.5, which that size is not on the current Goodyear website. They work OK but need something more agressive
http://www.goodyear.com/cfmx/web/truck/line.cfm?prodline=160700

Goodyear has come out with a Unisteel G171 LT in 8R19.5 that appears would work at least as good as the 124's, and probably better. Does anyone have any experience with this tire?
http://www.goodyear.com/cfmx/web/truck/line.cfm?prodline=160102

Really don't want to got to a larger diameter, but may have no choice.

Thanks