You will need to swap the spirals out, as the left hand twist grip has a pull action for the carb, and the right hand twist grip has a push action for the magneto advance on a standard set up. Both twist grips have a left hand spiral on the stock set up. Walkers or Greers will sell right hand spiral twist grips. It may be worth looking at replacing the cables and internals as well if there is any marked wear or kinks in the cables.
Grip Control Sleeve Assembled (RH Spiral) ( Not Indian Standard but some prefer this option)
Jon Szalay has a hand clutch set up on his scout for the same reason, anyone got any pictures? I have had a search thru my files but cant find them.