Disc brake swap stuff...large bolt pattern

Mount them either way, front or rear.
Just swap spindles side to side.
You can mount em facing to the rear, but then you can have hose routing issues. If you mount em to the front then disc brake 73-76 A body brake hoses fit like they are supposed to.

FMJ calipers are a great upgrade too. The A body caliper pistons are 2.60". M body, not sure about F or J, but M body uses 2.75" pistons in their calipers thats made of phenolic plastic. I was able to buy plated steel replacement pistons made by allied signal on closeout from rockauto to reload my M body calipers

This is a screaming deal for the price guys. If i didnt have all my parts for both cars, i woulda jumped on this great deal. Not trying to steal your ssle thread, Just wanted to give another heads up on why the M body calipers make a good upgrade.