Did you check the pressure with a mechanical guage? 16PSI at hot idle is within specs but the minimum spec is 13psi at 600RPM. Also above 1600RPM oil pressure should be 37-75PSI. Most people would consider that pressure normal as long as you are seeing a decent increase with RPM.
I am not too keen on the AMC V8's but I think these were known to have oil pump problems, and cover wear. Also most aftermarket gaskets are a little thicker than they should be which gives the oil pump gears a little more end play which could lead to pressure problems. Before jumping to conclusions there are a few basic things and small things that could be giving you fits, one is the oil filter, a lot of people have narrowed oil pressure problems down to using cheap (orange) oil filters.
Check out this website, it has a lot of products that address some of the oiling problems with AMC's