back spacing and sizes

QuickDart360 said
Your dart have a 8 3/4 or 8 1/4? 8 1/4 is narrower.

I removed the factory 8 1/4 BBP 321:1 sure grip. Gave it away since I have lots of 3rd member's.
Installed an A Body 8 3/4, with Moser axles with BBP and 11" drums from a Truck, Van, Sea Body.