The firing order on AMC V-8s are all the same (post 66 1/2). The only problem that it could be is that someone changed the distributor and not put it in correctly. The easiest way to find out is put the engine on top dead center as per the timing mark on the dampner and check the position of the rotor. It should be sitting on the number 1 post on the cap for the number 1 cylinder. Where ever it is sitting, put the number 1 spark plug wire on that post and follow the firing order that is casted in the intake. Often times, people will put the distributor in where ever it will mesh correctly (or incorrectly) with the cam gear and the oil pump keyway. So whoever had the car before probably had the dist. out of the car for whatever reason and reinstalled it wrong. Not really a big deal, just an inconvience for anyone who is trying to work on them