What donor vehicle to get disc brakes setup from for 72 swinger.

AndyF said
Depends on what you mean by "much newer". 40 years ago that statement was true but these days the parts cars are not much newer, they are roughly the same age. You used to be able to go to a wrecking yard and grab the brakes from a FMJ car for a quick disc brake upgrade. If you were smart you would also grab the 11.75 rotors and caliper brackets from an R body as well as a set of 15 inch rims and you were in cop car heaven. Find a set of big drums for the rear, an anti-sway bar off another car, and maybe get lucky and find a Feather Duster to part out while you were at it. But those days are long gone. Best bet these days is to call up Doctor Diff and buy a kit.

Exactly. The "newest" car that you could conceivably use as a donor for a '73+ disk swap is an '89 Diplomat or 5th Ave. But even those cars are not frequently seen in the yards anymore.

And as with any of the 73+disk swaps you'd need either a set of large ball joint UCA's that will not come from your donor car, or a tapered spindle adaptor from DoctorDiff.

Having pulled those disk swap conversions out of the yards for my own cars, I will also say that you're really only saving money on the spindles and caliper brackets. Because the rotors, bearings, seals, calipers, brake pads etc are likely not going to be in a condition you'll want to use without a rebuild. In the case of the calipers, the price the yard charges you will likely be higher than the core charge for a rebuilt set. So most of the time you're better off just paying the core charge. Hell even finding places to turn rotors isn't as easy as it used to be!

The first couple of brake conversions I pulled out of the yards I grabbed everything. After needing to rebuild/replace most of the stuff beyond the spindles and caliper brackets I stopped grabbing (and paying for) everything else unless it looked SUPER clean. Which it pretty much never was.

Bottom line is, I'd just buy the kit from DoctorDiff. No scouring parts yards, no laying in the dirt pulling parts of unknown history and condition, no finding out later you have to rebuilt or replace the stuff anyway.