Yes but will probably have to upgrade entire drive train...indexed started at 7 speed, so new deurailler and 7 speed freewheel for starters...you could go friction downtube shifters that will work with your current components. That's the route I would take, it's the most cost effective. If you really want indexed birifters or barcon, I would recommend buying another bike with the setup you are looking for and sell your current bike unless $ isn't an issue and you look at it as a fun challenge!