[Tchia65]

Backing plate location will matter if this truck is going to be in the weeds, need more than 1" to fit a brake hose between the rear and the bed. Otherwise as long as all the rears are being measured wheel mounting surface to wheel mounting surface than backing plate location doesn't matter. I have 2 15x10 chrome Rally's with a 4" BS that I can't use on my 58, I went with a explorer diff and need 6" BS.