Some background.
The Super Bee is based on the 440 model.
The R/T is based on the 500 model.
Other than the emblems, scoops and hood an R/T is externally the same as a Coronet 500. The R/T also used the same upholstery patterns and dash inlay pattern as the 500.
Therefore to cosmetically change a 440 into an R/T you would need to remove the 440 trim and emblems (as mentioned above), change the tail panel, change grille color (I think), change hood, change door pannel, change seats upholstery, change dash inlay and change to a 150 speedo (or change to a rally dash).
Chack out this site for lots of great pictures for reference.
http://www.andy440.com/Carmak
Riverside, Iowa
You will also need to add the upper woodgrain trim to the tops of the doors. If it were me I would keep the standard dash (as carmak said)and just find a 150 sweep style speedo as that will save some money the ralley dash was an option on RT's so you could order it that way. Some of the RT specific trim parts can get pricey compared to the more common Superbee trim which is pricey as well, but if thats what you want I say do it. 
