I've been searching endlessly for the right wheel, tire combination to get the style and stance that's been alluding me. I have a (ruff country) shock, strut, and spring lift that gave me a roughly 2" lift over stock stance. I've been to a few off road shocks here in the Houston area and get different recommendations from all of them. I wanted an off road wheel with off road tires that would give me a wider stance than stock would allow my tires to protrude past the top finder wheel wells. Nothing extreme,....... Maybe a 1/4in past flush.
I've read countless forums that seem to cater towards 7" wide tires but I wanted a wider stance of 9". This is common on most 18" rims I've looked at that fit the bolt pattern, which are few. I've tried looking at offset that would give me that without trimming or modifying fender. -12mm offset pushes my outer rim toward the outside fender by 1" on a 9" rim. That's considering that the factory rim is @ a +38mm like the websites I searched has said. When I measured my current sidewall to the outside top fender, it looks like there is 1 1/4" to flush. I understand that those 2"s of increase in wheel size has to go somewhere and if I use the -12mm offset, I would be adding 1" to the outboard side and by default 1" to the (backspacing) inboard side. Just to get this out the way..., I dont like any of the 16" or 17"x7" rims out there, nor the 17"x7" either. There are a couple of 17"x8" rims that I would consider but would put me needing a 0mm offset? If not...... please advise, because I am not understanding offsets.

Maybe this tool can be of help to you?
Wheel-Size.com, The world's largest wheel fitment database.
https://www.wheel-size.com/

Just remember, as you increase or alter wheel offset, you are changing the loading on the wheel hub bearings and may shorten their life as well as steering geometry.
Every change you make from OEM wheel size, offset, backspacing, etc... can have an effect on steering performance, tire wear, and suspension/steering components life expectancy.
https://www.gmnbt.com/ball-bearing-guid ... ing-loads/

Something to think about when choosing wheels:
The whole suspension geometry is designed around wheel offset. In somewhat simplistic terms, once the suspension design engineer decides what kind of wheel bearing/hub assembly they will use, the wheel offset is calculated to spread the load the wheel supports evenly across the wheel hub bearings. The load is not only the weight of the car, but also cornering loads. Too little offset will shift the load to the outside of the wheel bearings, and too much offset will shift the load to the inside of the wheel bearings, causing premature failure. But bearing loading/wear is only one of many variables that are affected by wheel offset. Castor is the angle produced through the suspension ball joints. These are the bearings that the wheel/tire turns on when you move the wheel left or right. The angle through the ball joints (Castor) is designed to end up on the ground in the middle of the tire's contact patch. If you move the offset very far this scrub radius will be adversely affected. This will make steering more difficult, and less responsive because you won't be using all of the tire's contact patch to steer with. The length of steering components like A arms also depend on wheel offset, so that camber changes as the wheel/tire moves up and down rotate around the center of the wheel/tire. All of these features of suspension design rely on where the centerline of the wheel/tire is. So, moving that point very far will not only adversely affect wheel bearing life, but wear on other suspension components as well. You might get away with + or - 5mm from the factory designed offset before you start to cause damage and adversely affect the handling of your vehicle.

kingpin/ball joint angle = steering axis inclination
caster = the angle in which the steering axis leans backwards at the top of the strut.
the intersection of the axis and tire = scrub radius
caster + steering axis inclination = included angle

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There is alot of information to absorb here. So by changing offset, I could damage my suspension or bearings. Hmmmm. The factory rims are 17"x7" +38. I've noticed that going to a 9" wheel,..... Let's say, " 17"x9" +30 increases inboard backspacing by 18.5mm and outboard face by 32.5mm. It would seems to increase road contact surface area may not put a strain on those components per.......

https://jr-wheels.com/et-calculator

I just put my wheel dimensions in, and then adjusted offset until I got the desired 1 1/2" stance. It also gave me an addition 3/4" in back spacing with the 9" wheels. So the offset wasn't as drastic as I was thinking, but I was hoping it wouldn't cause any clearance issues on the other hand.

Thanks WWDiesel for the great info:

Glad to be of help; hope you get it sorted out and end up with the look you want along with a safe and reliable vehicle.

_________________
Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount
98 Dodge Cummins 24 Valve

You're on the right track researching wheel offset to achieve the look you want for your truck. Finding 18" wheels with a 9" width and an offset that achieves the desired stance without rubbing might be difficult. A -12mm offset might push the tires out too far, potentially causing rubbing on the fenders or suspension components when turning. Excessive offset puts uneven stress on the insulated bearings, leading to premature wear.