His description doesn't make any sense.
The switch to LBJ UCA's was in 1973. That was for both the disk and drum cars. Disk cars were 5x4.5", drum/drum cars stayed 5x4" all the way through '75.
73+ disks were all single piston calipers. No 4 piston calipers for any 73+ cars, or any BBP cars, or any LBJ cars. If he has 4 piston calipers with those things they're aftermarket.
67-72 KH disks had 4 piston calipers, but they also had SBJ UCA's and the 5x4" pattern.
The LCA's are the same '67-'76 except for the location of the sway bar tabs. So, a non-sway bar LCA can swap '67-'76.
Lower ball joints are different for almost all of the different brake set ups, even the 9" and 10" SBP drum lower ball joints were different. But they all bolt to the same LCA, you just have to match the lower ball joint to the spindles you have.