In Jan. I'll be putting a 6" lift on my truck. I already have 20's on it and I planned on running a 325-60-20 Nitto Terra Grappler and I was wondering if I'll need to do any trimming or if there will some fitment issues with those tires, also this truck won't see any wheeling aside from the gravel road getting to my lake house. From what I've seen I won't have any problems, but I'm not sure. The wheels have 5-1/4" back spacing and I'll be using a Rough Country kit on it.

Should not see any problems at all I have 285 60 18 without a lift and they clear I was going to go to that size with a 4" lift and did not see any clearance issues.

does that measure out to be a 35x12.50 ?

Yes it does.

funny my buddy has the same truck as u but stepside . he has a faabtech 6 inch with 35x12.50x16's . he loves it , the truck is awesome and it handles nicely . hes the one making me wanna lift mine . he went and had a 3 inch bodylift put on and is selling the 35's for 37's . he threw a set of his buddys on and they dont rub at all so he went with those . and hes yet to crank his t-bars i dont think he will though

Nice. I can't wait to get this thing up in the air. One of our company trucks has a 6" Fabtech, 18's with Terra Grapplers and rides damn nice, except anytime you're going over a small bump and have the wheels at full crank, they'll rub the lower air dam.

I think you should be find with your wheels, especially since they are 20s. If you remember the pics I posted of the Yukon with the RC kit it is running 18s with 5" BS , I think. You should be fine, if anything you might have to run a 1/4 spacer, which isn't a big deal. Definitely keep us updated, the RC kit is cool. Are you going with the X or the EX kit?

Yea the wheels on mine actually have 5-1/4" back spacing so I shouldn't have any problems. My brother's shop has done a couple newer chevy's with RC kits w/20's and no issues. I'm just getting the X kit. I wanted to go with the EX. I actually sell RC, I work at a wholesale distributor for truck,jeep and suv accessories and we have a retail web site you may have heard of, TSETRUCKSTUFF.COM and I am getting the hook up on it and my RC Rep didn't have any EX's to spare so that's why I went with the X plus I've installed a few IFS chevy lifts and don't mind any cutting since it won't ever go back to stock. Right now plans are to install it all the first weekend of Jan. maybe sooner if all the components show up next week, one of the crossmember brackets were on back order, but as of this morning they were being powdercoated, so we'll see. I can't wait to see how it all looks. I'm also playing with the idea of stripping all the parts and having them powdercoated to match my truck, but I don't know.