I'd hold off on regearing. My 4cyl ran fine with 31's. You know thats not the end size tire, so wait if you can. I went to 33's and decided that was enough. The math for 33's on a 4 cyl says 4.88, so that's what I did. That was great for 33's. When I later went to 35's, it wasn't really a gear problem, but became a power problem. It was tough for the 4 cyl to spin the larger mass tires to accelerate, even though the tire size was only 6% larger. I then went to a V6 and kept the 4.88s. Life is great now (since the motor in 2004) on and off road.
'93 YJ, '02 GM 4.3 Vortec V6, SOA, dual ARB's, 8.8+D30(w/WarnHubs), 4.88 gears, 35" BFG KM2's, AX15, 15x7 wheels, NP231+4:1+SYE+2LO, York OBA, Warn M8000, no top or doors Apr-Oct.
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