Looking to put together a Colt AR15A2 rifle. I have a complete upper I'm trading for but not entirely sure what is unique about the Colt AR15A2 lower. I believe the rifle stock and pistol grip is different from the SP1 models but not entirely sure how.

Goal is to build a 1980s representative model of the M16A2 but not planning on getting too anal about it unless the differences are significant.