What can I use off a 96 caprice for rear discs brakes.I can get the stuff cheap,if its worth doing.I just cruise my car on weekends.

you can use everything except the rotors, the bolt pattern is larger for the full-size ride. make sure to use the master cylinder and proportion valve to make for equal brake force on all 4's.
I was able to do just the same from a 95 myself, Just had to use rotors from a third gen camaro with slight spacing of the mount plates to center the calipers to the rotors.
hope this helps. btw, excelent donor car for all kinds of useful stuff.

one more to add, use your power brake booster for the way it mounts to the firewall. the caprice master will bolt up to the booster - AFTER making sure to have at least .025-.030" clearance at the end of the pushrod to the master cylinder piston.

What can I use off a 96 caprice for rear discs brakes.I can get the stuff cheap,if its worth doing.I just cruise my car on weekends.

You could add rear disc brakes--but WHY? Unless you're running the car hard enough to overpower the existing drums, you're spending a lot of money and getting pretty much zero benefit.

Don't be afraid of rear drum brakes on a cruiser.

Watch out for the bolt pattern, Most of the disk brake setups are 5 on 5 (you need 5 on 4.75)

LK