Greetings: I have a stock suspension '89 C1500 2WD with OEM 15" rallys...does anyone know (for sure) the OEM wheel width, 6", 7"? I found the aftermarket wheels I want. I plan to use 2" drop shakles on the rear to almost level it with the front, slight rake. I think deeper dish rim on the rear is appropriate. How do I calculate (guestimate) the tire/wheel dimensions to get a consistent look front to rear, you know, filling out the wheel wells evenly? Wheel manuf. site says 6" rim on the front with factory size 235-75-15 (tread width 6-5/8) will result in same overall height as a 10" rim, if I go with 255-70-15 (tread width 7-5/8). Also, I can get within less than 1/2" overall height, if I go with a 275-70-16 on an 8 1/2" rim (tread width 8-1/8), getting better. Or, I can get spot on same overall height as the front with some "less than streetable" M/T or Hoosier 29-12.50-15 (10" tread width) on a 10" rim. I like 10" of tread width. My speedo would be really close with any of these scenarios. Does anyone have any experience with these calculations, making it look right in the process? Thanks for any help provided.