sway bar

ok... a little help here, can someone tell me exactly what the differance is between the 67-69ish sway bar, and the a-body bar that comes later?? I was under the impression the lower control arms were the same the whole way through the a-body run.. and from 67-76 the k-member should be just about the same except for spool mounts in the later a-bodies correct? Any info is appreciated