A very common problem with soft-skin kits are the wheels, and unfortunately the M977 kit has exactly that problem.
So why not take the wheels from the 2 resin HEMTT kits I own? I just took a quick look at them. They actually look okay, the tread is better and the steel rim look a lot more accurate than the one on the plastic wheels, but the resin wheels are smaller than the plastic ones. Looking at the 1/72 scale drawings in the Tankograd books shows me that the plastic wheels are pretty much spot on! Another problem is that the steel rims for the resin wheels, like the plastic wheels, will give you 8 similar wheels, not 4 for the front and 4 for the back which I need for a M977 according to my research.
So what to do? I know of at least one other set of resin wheels for the kit, done by Korean DToys, but they're not even weighted, but costs almost as much as the kit itself. According to the manufacturer's site, the set should contain "Front 4ea, Rear 4ea", but none of the photos I've seen has me convinced that the difference to the wheels are the steel rims. I would guess that the difference are the same as on the plastic ones, on the back of the wheel.
The tread patterns on both resin sets look pretty good and accurate. They're not the same, but represent the two most common patterns. According to my research these 2 patterns can be used together on the same vehicle. I've only been able to locate one other pattern, and that has so far only been on a single photo. Unfortunately the pattern on the plastic parts does not match any of these three patterns, which I'm pretty sure are the only three patterns (I think I read that somewhere in an U.S. Army technical manual for the HEMTT).
Not really sure what to do here. I might try to get some other AM company to do a set, or maybe just stick with the kit parts. Maybe I should dust off the old 3D software and make a 3D master myself, that might make it easier getting it produced somewhere.