I fully intend to run 35s at some point with this suspension setup. Currently my 33s are on Taco wheels and there's already an issue of rubbing in the rear because of the backspacing involved with the wheel itself- even with full flex I don't think rubbing would be an issue if the backspacing is correct.
I'm not speaking from experience here, so someone more knowledgeable please step in, but the geometry behind a lift speaks for a driveshaft extension regardless. If you wheel seriously of course. The axle is shoved further away from the body while the transfer case remains in the same position, thus lengthening the distance the yoke and driveshaft must cross. Whether you truly need to lengthen the driveshaft depends on the amount of lift you've got coupled with your needs for wheelin'.
I'm not speaking from experience here, so someone more knowledgeable please step in, but the geometry behind a lift speaks for a driveshaft extension regardless. If you wheel seriously of course. The axle is shoved further away from the body while the transfer case remains in the same position, thus lengthening the distance the yoke and driveshaft must cross. Whether you truly need to lengthen the driveshaft depends on the amount of lift you've got coupled with your needs for wheelin'.