I think we're all in love with the classic curves of AD truck bodies!
An original AD front end will drive great at freeways speeds if all the components are in tip-top condition. Disc brake conversion not a bad idea however. I guess the question regarding a total suspension change is, how long can you tolerate having your truck under construction, costing you time and money without ever getting to enjoy driving it while it's undergoing a major rebuild for months or even years?