I dont think fitting an RGV part to an NSR could ever be considered an upgrade!
That aside the nsr carbs sit side by side and bolt together with the throttle pulley on one end and one set of throttle cabbles, not sure on the exact set up of the rgv but I'm pretty sure the carbs are staggered so they wont be a straight bolt on. Plus the nsr carbs have the connectors for the 2t pipes on the carbs, again not sure how they work on the rgv but could be different. Probably better off looking for a set of later model nsr carbs.