How to Measure a rear end?

[YourBaby'sDaddy]

I have a 1966 coupe, that was originally a 6 cyl, and it now has an 8" 5 lug rear end, however, I don't know what car it is from. The total width of the rear end (wheel mounting surface to wheel mounting surface) measures approximately 57" in length with drum brakes.

When I was reading the "Rearend Swap info- FAQ" sticky in this forum, the measuments given for the Ford 9" rear ends measures from "flange to flange".

When talking "flange to flange", is it refering to the mounting surface of the wheels or something else? Sorry for the newb question.

 

[D.Hearne]

There are two ways to measure rearends widths. That's why the confusion. Some list the width as axle flange to axle flange. Others list the axle housing flange to flange (this is the flange the brake backing plate bolts to) If you're measuring for a narrowing job, both measurements need to be taken.