Flange to flange...

or backing plate to backing plate? Are these the same or different measurements? Anyone help me out...thanks.

 

no , not to me...when i measure a rear end i measure the disstance from wheel mounting flange to wheel mounting flange...that is the most important

from backing plate to backing plate is easy to measure beacuse you can do it with the wheels on and the rear in a car , but it means nothing to me

i sometimes see measurements of housing flange to flange , but that is useless too , unless you have the measurements of the wheel mounting flange to the housing flange

 

Flange to flange usually referrs to the outside measurement where the wheels bolts up. Backing plate to backing plate is the inside measurement between backing plates.

 

The flange is what the backing plate bolts to. The difference in the measurement could be the thickness of the flange.

 

Must be an echo in here.

 

Thanks guys, that helped to clear up some confusion...now, does anyone have a spare 8" or 9" they want to get rid of?

 

Wheel mounting flange to wheel mounting flange is MORE accurate...IMHO.

The difference in brake drums can throw the backing plate to backing plate measurements off.....

http://www.dfwmotorsport.com/Fairlane/9inchrearends.htm

Here is a site with widths listed.......for common Ford rear ends.....