401 ci engine

A relative just called to see if I wanted his 1970's jeep. He said it has a 401 ci BB engine that runs real strong but the jeep itself is kinda rough. I'm just wondering if any of you are using a 401 in any abody or what the rep they have overall. This is a big block engine size from AMC correct? Any info appreciated or websites that may have info on them. I did some searches on yahoo but haven't gotten any real good info as of yet. Thought someone here might know something or point me in the right direction.