All three brake systems offered on A-bodies from 1962-1972 used the exact same suspension geometry. The significant differences between the 9"x2½" and 10"x2¼" drums and the 11" Kelsey-Hayes discs were the spindle and lower ball joint. Otherwise, all three brake systems share the same suspension components including upper control arms (UCA), lower control arms, brake strut rods, tie-rods, shocks, and upper ball joints. The difference between the lower ball joint on the disc brake cars and drum brakes cars were that the disc brake lower ball joint is a heavy duty version of the drum ball joint.
When rebuilding a drum front end, it is possible to use the 1966-1972 disc brake rebuild kit. This kit is identical to the drum brake kit except that it comes with a heavy duty lower ball joint. There is a difference between the 1962-1969 drum and disc ball joints and the 1970-1972 drum and disc ball joints (need to check differences!).