My truck measures 37.75" on one side and 37.5" on the other.

MOPWR2U do you have a hemi or the 4.7? I'm sure the Hemi outweighs the 4.7 significantly and therefore SARGUY's truck would squat more in the front than yours. If you do have the Hemi than maybe you guys measured your trucks differently or your truck was sitting at a funny angle. There are too many variables to people just listing their measurements.
The trucks would have to be measured on a jack with the tires off the ground, this is when you would see your spacer in effect.

 

My truck has the 5.7 Hemi. In order to avoid the differences from one truck to the next in tire height and tire inflation pressure, we could measure from the center of the hub to the bottom of the fender. Mine is 21 1/2" on that measurement.

 

Mine measure exactly 23"

 

Well there you have it, the TRX model is "at least" 1 1/2" higher due to its suspension than a Laramie is. The reason I say "at least" is because the TRX has fender flares and my Laramie is a monotone Laramie without fender flares. The bottom surface of the fender flare you are measuring to may be lower than the bottom surface of the fender I am measuring to.

MOPWR2U

 

Run 35x13.50 and call it a day. If a 4 inch lift will clear 37s from mopar that means no cutting. If anything run the new wheels with an offset to have the tires stick out. If your gonna use the stock wheels have a shop mount up 315s to see if they fit

 

I am at 22" on a slightly not level surface. The fender flares have to play a big part.

 

Yup the spacers are probably 2" then. Didnt even think about the fender flares and now that i look at it compared to pics of Laramie's seems what you're saying is correct

 

i would run 35x12.5 max. 13.5 would be too big. A 4" kit will not clear 37's. The 4in will clear 35x12.5 and the 6in kit will clear 37x12.5.

 

35x12.50 would be the max.

 

I have 37x13.50s on the Jeep. 13.50s are too wide to fit in the track at the local drive thru car wash . The widest tire that will fit through the car wash is a 12.50, and since I have a black truck that is critically important, LOL. I'm getting 35x12.50s and have a set of 2" spacers on order. I should know within a week or so if the 35s are going to fit. If the 35x12.50R-20s don't fit I'll try a set of 275/65R-20s (11" x 34.5").

MOPWR2U