Here is my LJ with 4.5 inch suspension lift, 35's and 4 inches of bump stop. You can see that 4 inches of bump stop is pretty much what is required to keep the tires from hitting the fenders with 35's regardless of lift height. They can't really stuff any further into the fenders. This set up works great off road and flexes like mad.
I've got some pos 4" hodge podge lift that the previous owner had on it, stock dana30/35 open with 3.07 gears, mostly stock control arms, no sye no double cardan rear driveshaft and I had stock fenders until last year. I'm running 35" bfg km2's. I do have a bigger than usual bumpstop. Blew out one front fender after a jump that's when I got the tube fenders. I never rub full lock, never have. Does it ride the best, no. Is it fast, heck no! But it does just fine on the streets and does surprisingly good in the trails. I do have an hp30/ford 8.8 with 4.10's waiting to go in with a jb conversions sye, a CV driveshaft, and adjustable control arms...
They stuff well and rub just a little. I agree with previous posts about the stock D30/35 not being suffice for 35's. I am going with an 8.8 rear and going to build a custom triangulated 4 link with it and then do a super 30 up front.
33's worked great on this setup and I could stuff the hell out of them. I got a hell of a deal for the 35's so I went with it.