Brian,
I added an oil cooler to the transmission as well. One more thing I did was to wire the electric cooling fan to a switch on the dash so that I could turn it on continuously while grooming if overheating or moving slowly. Seems to work pretty well to help things out.
Steering is another thing. Simply can't try to turn the wheel when not moving. Your tracks have more surface area on the ground than mine, which makes it even tougher I am sure. Ram steer would probably work OK. Try installing live hydraulics off a pump mounted where the air compress is suppose to be mounted. You will constantly be steering the drag with ram steer.
One issue though, is that you have 4 sets of tracks on the ground (like on a Tucker Snocat) so that I doubt the ram steer will aim you towing vehicle like it would with a double tracked groomer like a Bombi or PB. Perhaps try pulling a shorter grooming drag that drags around corners easier, or lift it up on sharper corners so that only the compression plate is on the trail surface rather than the length of the drag rails.
For what I do, I get a heap of grooming done in deeper snow with just a roller first, then use an 84" Ginzu Grooming drag (
www.yellowstonetrack.com) when snow is not so deep or firmer or needs renovating.
Good luck with it. Your vehicle is
in better looking shape than mine these days, but it still works OK when I need it.
Lou