73' B3 340 Duster pro touring build
I think the 20" with the 29x15 Mickey Thompson S/R would look great with the matching 18" 26x8 upfront. :thumbrig:
What gears you running? 4.10 or even a 4.30?
When I originally had 29" M/T Sportsman Pros I had a 4.30 gear. When I went down to 26" tall drag radials I switched to 3.55s. Same RPMs per MPH with either setup.