I run 4" and a 1.25" BL. It was just fine for 35's.
1997 TJ, NEW FRAME, 4.0, 5 spd, d30, d35 aussie locked, np231 RR sye, tom woods driveshaft, 4" RC n20 lift, adjustable upper rear c/a, 33x10.5x15 BFG KM2s
1945 Willys MB, all original right down to the tires, 30k miles, 250 miles on rebuilt L134 engine. + 1946 Willys CJ-2a, barn fresh, new 6.50x16 NDTs, 15k miles
I have a 4 inch longarm lift, plus a 1.25 inch body lift. I have 285 series Duratracs and they just barely clear the fenders at full flex and zero bumpstops. They look like they rub but I can still get a pinky finger between the tire and fender.
There's a lot of wheel gap, especially since I don't have fender flares on.... but I don't care.