okay so there is some confusion for me measuring backspacing on my 15x7 police wheels ,

i have both 15x7 and 15 x 8 wheels, but now i think i will just use the 7's

i have heard to measure backspacing to measure from the bolt face out the the outer lip like if you place a straight edge across the wheel, but i just read a post on this forum that contradicts that and many other tutorials i have read

"I'd like to point out the importance of proper backspace measurement. I've seen police wheels listed as 4.5" BS and that isn't true.
Even some wheel manufacturers (namely Centerline) use an improper measuring system.

Backspace should be measured from the bead (not the outer lip) to the area that contacts the hub/rotor/drum.
"

so what is the correct way, to the outside edge or just to the bead seat, if i go outside edge then im at like 4.5 if to bead seat its like 4.25 on my police wheels.


so if i indeed have 15x7 with 4.25 spacing , could i run a 255/70 on back and then go with like a 215/60 on front?

im trying to get that back end to stand up higher and the front be lower , the classic muscle look , what tire on the front would you go with on a 67 to get that back end standing up look?

thanks for any help
i made a mess of this forum with all the contradictory information.

just for clarification i have 15x7 not 8" cop wheels , thanks