I have been running those same tires on my M817 for 5 years now. Finally got my first flat this year, **** nail. When you say split ring wheel, are you talking about the two piece wheel that these tires are designed to be run on? They have a ring of bolts that hold the two halves together and a rubber seal between the two halves. I wanted to make sure that you are not trying to put 16.00's on your stock split rim. You need to make sure that you are using a HETT style wheel. I use the crap out of my truck, I run around at 48,000 about half the time. I move my 26,000 pound Excavator behind it just about every week. I run my tire pressure at 60 psi. With my stock fuel pump turned up to 2400 rpm the truck does 75 MPH, comfortably, no white knuckle ****. It handles better on the road too. When my speedo reads 47 mph, the truck is doing 60.
If the tires all hold air, are mounted on the correct wheel, have some threads showing on the outside of front lug nuts and don't look all weather checked, I would drive it home. Just have an air hose and a plan B just in case. If you are one of those guys who don't like to take any chances, put together a full size spare and tools to change it before you go get it.
Papacracker