Can anyone decipher/elaborate on what rods will/will-not interchange thru the years, realizing that chal/barr need to be different. (within . Per parts books it changed after 70 then reverted back in later years.
-----------Barr--------Challenger

70HT.......2963358/9....2963360/1
70Conv....2964300/1....2964302/3
71HT.......3570332......3570334
71Conv....3570333......3570335
72-74......3570332......2963360/1