FYI spindles interchange from the following cars:
68-74 Nova, Omega, Ventura, Apollo
67-69 Camaro, Firebird
67-72 Chevelle, LeMans, Cutlass, Skylark, Monte Carlo, El Camino, Sprint
all 67-68 models used 4-piston calipers and are very valuable, and expensive to rebuild. Any 69-72 used single piston, and are cheap and effective. Do yourself a big favor, and only consider the 69+ brakes.
I do have an extra set off a '69 Nova, but I'm not really sure if I want to sell them. Make me an offer I can't refuse