I did some calling. The nearest Rim Guard dealer is 45 miles away. $275.00 for them to come to me and $165.00 for me to go to them (Plus, $52.00 for brass valve stems and labor to break the beads and install). Much better!! I may change the stems myself and take the tires to them, I don't have a trailer for the tractor.
He recommends 15 gallons per tire (right around 50% full), not the 21 that Rim Guard states. I'm fine with that. I do know John Deere recommends only filling their tires to 40%, not sure why, but in my mind, anything above the level of the axle is just contributing to becoming top heavy. But then again, I think different then some people.
Anyone have suggestions for a good brass schrader valve for air/fluid?