I also posted this in the frequently asked questions under Frenchy read this first thread, I got tired of trying to find on the internet what my back space and offset is for my stock wheels so I pulled one just measured it myself..
Watch these videos..
Well since I could not find the back spacing or offset for my stock 18x8 wheels I pulled the tire off and measured myself just to be sure so when I go shopping for my after market wheels and these are the numbers I got..
To start these wheels that the manufacture lists at 18x8 is wrong it measures 18x9
this will help you determine what kind of wheel to buy and what kind of tire you can run on your new wheels..
bolt pattern which all wheel manufactures list for our trucks is 5x5.5 which is 5 lug by 5 1/2" or 5.50 or 5x139.7 millimeters I measured on my wheels 5 3/4" or 5.75
Back spacing on these wheels are 5 1/4" or 5.25"
offset for these wheels are positive offset of 1 3/8 to 1 1/2 or right around 37 millimeters
what seems to be the norm the more the the after market wheel gets closer to the centerline of the rim or 0 offset or in the negative offset, it reduces the tire size you can run because of it pushing the tire out away from the truck and then run into rubbing issues..
Here is where it shows you how to measure your wheel if you feel the need..
Update I just found out what our stock offset is and that would be +38 I was only Millimeter off LOL