Unicorn Hardware, pre 69 front 10 inch small bolt pattern any advice ?
Really all I know is what is in the Plymouth & Dodge service manuals, supplemented big time by the Master Technician's Conference and TSBs.
I never had a real issue with the '67 brakes, but was curious as to a few things. One was that the parts books (back when I bought most all replacement items at local parts stores) either didn't have the disk/drum option listed, and/or had conflicting information about drum parts and interchangability. I tried to resolve as much as I could by going to Chrysler dealerships that had the old books and would let me look stuff up. Later of course when the Imperial Club and Barry digitized those MTSC and other dealer literture, the pieces came into place.
Another curiousity was the drum hardware for police, taxi, etc. that was adopted for racing (and road rally). In those applications, self-adjusters were not usually used. As far as I know, that did not change when the new self-adjusting system was implemented.
The new self-adjsuters may have been a minor problem that the factory decided was worth implementing in the interest of reducing even minor customer anoyances. But not frequent enough of an issue to encourage changing the pre-69 cars to the new system.
I made a crib sheet for the rear 10" drums
151 is the Ford version but will work. 256 is probably the Chrsyler version. Aftermarket prefers to go for one size fits most, close enough so 256 is rarely seen.
288 is rarely found, but Craig probably has some. I found a set of Firestone branded old stock 288 on ebay, although have not used them.
Another thing I look for, when possible, is the edge lining codes. Makes no sense to have a friction lining with a lower rating than factory linings. of course that means finding original factory linings that have edge codes... that's another rabit hole.
It is interesting that even aftermarket manufacturers back then often used a different lining material on the primary and secondary shoes.