I am the very proud new owner of an '05 GMC Duramax CC SB in Victory Red, and with that a new member here. The mini me tires have got to go. I went to our local Les Schwab tire center to inquire about some 315's. He warned me against changing the torsion bar settings, and told me that I would need a 4" lift for 285's and a 6" lift for 315's. He said changing the torsion bar setting will cause premature CV joint aging.

I am looking for a more overall squat stance rather than the lifted look, but I like the beefier tire look. Do his lift suggestions sound a little over-kill?

Thanks!

Had T-bars cranked all the way for a while with 285's. Steering components (idler arm, pitman arm, etc.) will wear out very quickly and puts that much more strain on the rest of the front end components. Not to mention the ride quality sucked. Put on lift kit and everything is back to reasonable angles. Ride quality 10 times better as well.

Do you think 315's will go on a 4" lift OK?

it can be done, but you will probably have some trimming to do. -Jeff

Bummer...not really wanting to take a knife to my baby just yet...:(

I was informed that for 315's (35) you need a 6 inch and for 325's (37) go 8 inches. This is with no turning of the torsion bars.

I'm running 315's but have a 6inch lift. See me ride and add-on by clicking on the link in my signature below.

LATER!

Nice rig! I decided to go with a 4" and 285's for now....I am already going to the poor farm over this truck. I am sure everyone here has felt that pain...

what about a cognito leveling kit? I believe that will work for 315's and maintain near stock front end configuration, I think.

Dan

The biggest problem fitting 35's on a GMC is how far down the plastic fascia goes on the front bumper. 35's WILL fit with with a 4" kit, do it all the time, may have to tweak T bars a bit, more personal preference that fit issues, most want a bit of "bulldog" to their truck, that is the front a bit higher than the rear. H2 takeoffs will work with T bar tweaking only because of the offset built into the wheels. Check pics on my sig... 35's with rancho kit, NO bumper trimming

WOW... "with" twice... WHOOPS

If cash is tight,buy the Cognito leveling kit. You can run a 33x12.5 or metric equivalent(sp) on an 8' wide wheel with 4 1/2 backspacing with no or very little trimming. As a bonus you can use most of the leveling kit to upgrade one of Cognito's 7"-9" or 10"-12" lifts later. That way no parts are wasted.

285's will fit with torsion bars cranked up & alittle trimming

285's will fit without touching the T-bars and with doing a little trimming to the bumper. They will rub on the left wheel on a full lock left turn though.

probably depend on what style of tread, all-terrain or mud

I have had 285's on my truck for 1 1/2 years now (since day 1), torsions cranked, and zero issues with premature wear or failure of any components. WAskier is correct on the rub issue on full left lock turns. 13k miles & 2 rotations now, no abnormal wear on tires, all ok. 4 inch lift would eliminat full left lock turn rub as it would bring the rub point above the tangent point if the tire.

Bill

yup, 285/75/16 's (at least the Mud king's, i think some run just a little bigger)will fit, crank the Tbars a couple rounds and trim the front plastic fenderwell on the driverside where it sticks out to go around the washer bottle resevoire.

Thanks all!

I am having the 4" lift done today. I had an extra pair of 285/75 r16's from my Ford that I am having them put on some 16x8's. Can't wait to see it. After these tires are worn out I'll see what my options are then.

Notice pic's and Signature. 2wd 3" spindle lift in front and 315x17 H2's and 2" lift blocks in the rear to level when towing. Had to trim the front facia a little bit (Rounded off the bumper) and tied the inner fender back....no problem! Hit a big bump-problem!!