my 2.9 that has almost 200k turns 33s (bias ply TSLs on steel rims) with 456s gears. i have also went to the m5od1 trans from a explorer so i lost some gearing in that regard. i am happy with the performance. my tires and rims are VERY heavy for 33s. my buddy ran 34 inch LTBs on aluminum rims with 307? gearing in a 4liter 5 speed truck. the gearing was terrible and it was not super safe but it moved, slowly, but it moved. i would be content with a 4liter 35s and 410s but nothing less on a trail truck. DD or hauling weight i would NEVER run less that 456s.
86