[4tiresngas]

You can put the 71's on the 72. The problem comes when you try to put 72's on older trucks. The 72's have longer crank arms on the window regulator and latch to accomodate the thicker plastic door panels.

To install the older panels, you'll likely need the retaining bar that goes across the top of the panel. It is held on with screws...no big issue. On the bottom, you wil need to get the pop in nuts (metal or plastic...probably on the help aisle of your local parts store) and pop them in so you have something to tighten your bottom screws up with.

That's how I remember it. If I'm off, I'm sure someone else will chime in.

Good luck.