Did I Screw Up OR Get Hosed???

Base model early A-bodies got the short 9" arm rest base and pads both front and rear, cars with higher trim levels got the 11" base and pads in front and 9" base and pads for the rear. And if you happen to own a Canadian version, oftentimes they came with the extra long 16" base with an 11" pad in front, and I've seen both 11" and 9" base and pads in the rear depending on model and trim level.

All three different lengths of the bases will fit as the mounting screw holes are spaced the same no matter what the size of the base is.