Found it. If anybody's interested it's a Power Trax, part #pt92-0782-2802. Fits a GMC IFS with 6 hole wheels.
A couple of dealers say they don't carry it since it's been know to cause the vehicle to dart from side to side on the highway. That's not a problem for me since there are not many roads here.
I'm also looking for a spool for the back but I've been told that there is none available for a 14 bolt C clip rear axle.