Stock Wheel Info?

[Mazer18]

I'm looking to replace my wheels but don't know how to get the proper fit. I just want the same size but a different style. Mine are currently the Work Truck model but I like to get the 5-spoke or maybe an aftermarket perhaps. The 5-spoke would be fine though.

 

How do I find a correct fit though? Do I have to match bolt pattern, rim size, backspacing, offset, and width? My bolt pattern I believe is 6 on 5.5 and rim size is 17". Does anyone know the factory backspacing, offset, or width though?

[Daryl LBZ]

I think I saw somewhere the offset is 30mm and the backspacing is 6", but dont quote me on that.

[asilverblazer]

GM says offset is 31mm that makes backspacing 5.75". (If the wheel is 7" wide, which I don't recall for certain.)

[cbsaf]

So, since 8" aftermarket wheels are definately going to be easier to find than 7.5" wheels, what would the offset be on an 8" wheel with 5.75" of backspace? 12mm?