I've considered it too. They will bolt right on. They have the same exact base pattern and gasket.
There are only one style of A-body sport mirrors. They actually offered them on 70 B-bodies and they take the same exact mirror.
BTW the 70 E-bodies use the same top mirror housing, just the bases are different. They used to sell repro bases to convert A-body mirrors to E-body. That's why you will see bare A-body bases for sale.
