My experience has been that the only physical difference is that some come with oval bushings and some with round bushings on the lowers. Not sure exactly why, could have been big vs. small block. I've interchanged parts for those years without problems.
My 2 cents. Gene > Part number-wise, according to my GM parts book: > Group 6.168 ARM ASSY-STRUT, Steering Knuckle Upper and Lower Control Arm > Assy. > 64-72 3974217 L.H. upper > 3887062 R.H. upper > > 64-70 > 71-72 wagon > 71-72 (400 w/4bc,454) 3990509 L.H. lower > 3990510 R.H. lower > > 70-71 (exc. 396,400 w/4bc,454) 3967769 L.H. lower > 3967770 R.H. lower > > 72 (exc. 396,400 w/4bc,454) 6263617 L.H. lower > 6263618 R.H. lower > > Apparently, for some reason the 70-71 and 72 lower arms are different for a > small block car. (?) > > Dale McIntosh > TC Gold #92/ACES #1709/NECOA #41 > GR8PMKN FOR SALE > DalesPlace My 67 SS and 67 El Camino > ChevelleStuff Decoding info on 64-72 Chevelles > MidwestChevelles Midwest Chevelle Show Information > > > >
