What backspacing for Mickey Thompson classic lock wheels?

[Jamesval035]

All,

Does anyone have the Mickey Thompson classic lock wheels in a 15x8?
If not, does anyone know the backspace for the 15x8?
I searched and searched and found that it could possibly be -30 offset which is 3.13 BS (way too much for my liking) and another that says 3-5/8 BS.
The 1st pick is what I found on the net and the 2nd is the pic I’m looking at.
Please advise? Thanks

 

[Jerry Bransford]

3 5/8" of backspacing is the right choice there. 3.13" isn't enough.

 

[Jamesval035]

3 5/8" of backspacing is the right choice there. 3.13" isn't enough.

Thanks Jerry.