[special-K]

You need to find the 4wd & Off Road forum for this type of question.

I rub 35s with 4" lift and with 6" lift 37s can rub, too. I run in those combos and am careful, but ditches is where they will rub...or any twisty situation. With bad body mounts 35s can rub pretty easy with 6" lift and 10" wheels. All this is from personal experience. I always ran 10" wheels and going to 8" can be all the difference.

Edit: When I did 6" on a '72 K/20 I had to lengthen the rear shaft 2". Also longer e-brake cables made, as well as brake hoses (I do hoses w/4",too). That is all I did, other than same lift steering arm as 4" (sold as 4-6). No transfer case drop or anything to the front. That was the only 6" all spring lift I've done on a 67-72. I had everything to do it again, tires/wheels mounted and ready, but decided I'd rather stay 4" to go 35" and down. I was thinking 2-3" with 285/75s on 8" or 255/85s on 7" (maybe 8) in the long run, but still wanted to use up the 37" and 35" tires on vintage wheels I had. I decided rather than go through all that, I could get the 16" steelies these days, so sell all that 6" lift/37" tire stuff, go to 4" so I could run the slots, and it would still look right once I end up with the sizes mentioned above. I'll probably go one or the other of those and another set of 35s. All in 16" with 8" wheels.