How to move calipers to the rear of spindle?

The front mounted caliper on an A-body is the same part as the rear mounted caliper on an F body. Just the right and left part numbers are switched; that is the part number listed for an A-body right is a F-body left.

When you switch the spindle & caliper side to side to rear hang them you do want to use the F body flexable brake lines so you have the correct length. From a functional standpoint the caliper doesn't know or care if its front, back, top or bottom, it works the same: may be some impact on the action of the suspension but that's a different discussion.

No they aren't. Mopar engineers designed different calipers for the rear hung applications. The hose routing is different on the rear hung calipers. These swaps work better when you use the correct parts.