Key is the rear Teraflex tire! Mounted on a stock 4.25 wheel(needs to be replaced, planning on 3.5). Front I have a D.I.D strong 1.8 with a Heidenau full knobby(whatever CJ stocks).... I run 25psi front & rear, don't believe in airing down with this much weight. I have an extra cooling fan piggy backed via relay off the stock unit with the lower temp sensor. Was only moderate warm(70s), bike ran perfect, 2nd & 3rd gear mostly spooled up. 1st gear was almost unrideable in the sugar sand.... Air speed velocity of a unladen swallow???? Ha!!! That Teraflex IS DOT legal......so should qualify for Sonora....jus saying I ran my bike with this similar set-up, loaded in Nevada heat (approx 90 degrees) with Grinderman, bike got very hot making some big climbs. I really wanna explore the ideA of adding an oil cooler. Fairly easy I think....not sure how effective it would be be. But wanna keep the bike crashable & easy to repair( not a bunch of custom parts).