Some of the worst tires I've EVER changed were 10.00-16.5 skid steer tires. Actually these were 10 ply Firestone DuraForce radials with the heaviest bead protector I've ever seen... and hardly any drop on the wheel. The bead lip on the wheel will bend before the tire finally goes on.
16.5-16.1 floaters are also pure devils.
A 20.8-38 should be a walk in the park.