[chilidawg]

I'm not on here trying to teach my grandmother to suck eggs but..... You do know that the front brake on the '83 only operates one of the front rotors?? So if this is news to you then try and operate it using the back brake.

 

[chilidawg]

The caliper did not change, only the operation of it, as long as you get a dual piston caliper that is handed correctly, it will work.
But there are a number of ways to get them to free up, you can replace the bleed nipple with a zerk fitting and use a grease gun or easier still, reinstall it, bleed it and push those pistons out using the brake lever. Some also say that ATF works good as a dip, takes a while though.