B-body lower control arms are shorter than A-bodies by about 1/2" if I remember correctly. I've gotten A and B body cars sitting with the K-frame 2" above the ground by cutting the lower bump stops to 3/8" thick, and the tires at 1° negative camber with the offset upper control arm bushings. It looks to me like on an A-body, the upper control arm mounting points can be separated from the body and relocated a few fractions of an inch, and rewelded where desired.