Just had my 285's mounted and installed, I can see I will need to trim the front air dam a little on both sides. Also on the drivers side front of the tire it rubs the bottom of the inner well, will need trim a little there as well.

Question. Drivers side rear of tire what is behind the fenderwell that makes it stick out, tire will rub there as well.

Note: Truck is 100% stock, have not touched the tortion bars, will I need to?

Thanks:ro)

285/75/16 Goodyear MTRS makes it look like a different truck!!!):h

The left front has the windshield washer tank and the rear is E brake cable, 2- 1/4" holes and a couple of long nylon cable ties will take care of the problem.

I use a 4" die grinder w/ a 1/32" thick cut off wheel to take care of the airdam.
Just don't touch the hot plastic right after u cut it.

If u look at the center of the wheel/tire is above the airdam so if u turn up the bars it will get closer to the airdam.

Thanks, tied off the brake cable,"wunder what those holes were fer"" DAAA if they hit the holes. Trimed the front fider well to just below the washer bottle and trimed the front air dam with a sharp razor knife. Sweet:ro) ):h :D

Do the trimming and use the zip ties. I have mine cranked to level. No rubbing.

On stock rims, I just cranks the torsion bars! Nothing else done!

I used zip ties and cranked the torsion bars 5 turns.. Torstion bars only gave me 1 inch.

On stock rims, I just cranks the torsion bars! Nothing else done!]

On stock rims some GMCs are ok but due to assembly plant variations some have to do a little trim on airdam.
Seems Chevy has a little more room.
All the 03+ trucks I've had needed the inner fender tied front and back.

One thing is whether you are Chevy or GMC. It seems the GMC has more clearance. I put 285's on with no adjustment or trimming. Bolt on and drive.

How hard is it to turn the torsin bars? Is it something anyone can do? Just wondering. I was thinking of going to a 285 tire. If I have to do the torsin bars I may just go with the 265. Also how far do the tires throw the MPH off on the gauge?

Cranking the bars is easy. Do a search on here under that subject. Don't go over an 1-1/2 and get an alignment done afterwards. My speedo is off around 8% if I'm remembering right. Here is a picture of what you are looking for. http://www.dieselplace.com/forum/showthread.php?t=1427&highlight=cranking+torsion+bars
Jack up the front to take the pressure off of the t bars before you start cranking. I think 5-6 turns is pretty standard.

With the 285's my spedo shows 70 actual is 75-76 not a big difference.

the rule of thumb told to me is that on the 285's forecast a 10% difference from the 245's in regards to the speed. the spedo will read that much slower. I checked, with one of those mounted radars on the street, and it is pretty close and a good estimate.