Wheel Backspacing Help

[Jameson]

I want to put some 18 or 20" custom wheels on my nbs silverado. Id like to run 32" tires that are maybe 11-12" wide. Im trying to find out what backspacing I would need to give it the wider stance. The picture below is what I like. Not too drastic, so that I get bad wear on tires and drivline. But just enough. Can someoe help?

 

[iminaquagmire]

That truck looks to have a knuckle lift and so the wheels are out farther than normal. You can buy lower offset wheels to get there too. Stock are +31mm.

[Jameson]

so lower number is lower offset? I think I answered my own question.