OMM that sucks that you didnt know and scrapped the 10" finned drum cars, because those UCAs are like effing gold these days. I happened to enquire about a set of BBJ A body UCAs and that they are hard to get with my mopar junkyard buddy, and he didnt have any. Then he mentioned 73-75 SBP 10" drum cars. I thought the same thing SBP = small ball joints. He informed me of 2 different SBP drum setups from 73 up. The 9" and the 10". He stated the 9" ones were essentially the same as the 72 down. But the 10" ones used the BBJ.
Based on the TSB the 9" ones went away in 73, but I am betting that they used up what they had in assembly line inventory to get rid of it. However my friend told me to be sure of the drum size and fins before wasting my time to pull them.
I measured a K772 in my shop, took my tools and a 6" scale to the junkyard where the 74 Val was at. I wasnt sure if it had the finned drums or not. As luck was on my side, it did. In my boneyards,All the A body disc brake stuff was gone and used up long ago to the roundy rounder dirt track.
I did get big rotors, calipers, and caliper brackets off a 78 magnum, and a 69 cordoba for both cars. My 67 has A body disc brake spindles, and the B/C body rotors and calipers. My sons car uses M body spindles, and the same B/C body rotor/caliper setup.
