Ronnie, update/backdate is available to Street Prepared (and to classes that inherit rules from SP) - chapter 15, I believe (I think it's on the first page of SP rules). So, no update/backdate in Stock. What you can theoretically do in Stock is a package conversion, which is to convert a car to a different package that was available that same year, but it must be a complete conversion (you can't pick and choose what pieces to convert). And example of this might be the conversion of a base model Miata to that of the R-package Miata. If you were to do a package conversion to the Cobra, you'd have to make it into something you could have optioned from the dealer for that model year.
Regarding Tri-State, awards are for individual classes.
Mississippi Region #83 SS / #97 STU