I had a 22ret( turbo 22re) in my truggy , r151f r speed, dual cases with 4.7's in back with 4.10's in axles on 39.5's and 38.5's. The 38.5 Tsl/sx's were hands down my favorite tire to run and with my 4.7 rear case I rarely ever had to put the front case in low. My overall crawl ratio was around 197:1 in double low first gear. The turbo helped the 4cyl a little bit
My yota buggy had a 22r on pane, 5 speed, dual stock cases, 4.10's in diff and 38.5 tsl/sx's. I just kept it in double low all the time