Sounds like standard 8-3/4 A-body axles. I have a stock one here and they measure 27-11/16 from splined end to the inside of the flange. I think A-bodies are all that originally used the 4" wheel bolt pattern but I'm not positive.
fishy, thanks for looking into that for me. I seemed to remember it being from an 8 3/4 rear but wanted some verification. As for all A-bodies having a 4" BP, I think it is true for all the A-bodies up to '73 but I believe the post-72's came with 4.5" BP on the 8 1/4" rears and on the front disc setups. I should know this after all these years but if it is not correct, someone please correct me.