401 are great motors. You will first need a new timing cover/oil pump housing as they are alum and should always be replaced with a build/rebuild. If you look at BJ's offroad, they well them along with a midplate that will help the housing to last longer and oil pressure to stay higher, longer. The stock heads are good, but if you want some great flow, go with a set of edelbrock alum heads (port and polish them), Edelbrock Performer air gap intake, 750 carb, Summit Racing K8601 cam, pair of good headers with 2.5 dual exhaust, either an HEI conversion or upgrade to all MSD, and a good set of pistons.

That there would be a good start. Also look into a high flow wather pump but only go with it if you are going to use an alum radiator, which I would recommend.

 

I would look up for stuff on Summit Racing. A lot of the money is gonna go towards machine work for it. You might also want to talk with some of the people of at www.IFSJA.org as there are some guys on there that have some well built up 401s which are the same ones that came in the the AMC cars.