Originally Posted by Bryan59EC
Try to locate the brakes/spindles etc from a 68-72 Chevelle
Then the 14" stock disc wheels will be fine
Just to clarify, spindles from all 1964-1972 A-body cars, all 1967-1969 F-body cars, and all 1968-1974 X-body cars will interchange. The steering arms bolt on, so you just need to swap your existing arms onto the other spindles. Disk brakes were factory offered starting in 1967, but the 67-68 calipers were the four piston units. These calipers are prone to corrosion and seal leaking, and sleeved versions are expensive, so I'd avoid them unless you really want "correct" 1967 calipers. The 69-up disk brakes used the single piston sliding caliper, which is readily available at any parts store. Just be aware that in most parts of the country, you are unlikely to find one of these cars in a wrecking yard. Restorers and ebay sellers have pretty much picked the yards dry.
Also, as I noted above, not all 14" wheels will clear these brakes. You need to be sure the wheels were designed for disks and have the additional backside clearance.
Finally, you can actually machine your drum brake spindles to accept the caliper bracket. The caliper brackets and dust shields are readily available as repros. Everything else - rotors, calipers, hoses - are available at any parts store. Here's one link to the machining required: