I've had no experience with this type of swap, but your question causes me to pose a few of my own. Are both the same diameter? Same number of teeth? will the trans pulley accept a 1 1/2" belt? How wide is your rear tire? My 97 ultra has a 1 1/2" pulley but Can't run anything wider than a140-85-16 or the belt will rub on the tire.
u know I didn't even think of the trans pulley lol. They both come in 70 tooth and I only have a 150/70/18 rear and looks like I would have room for the 1-1/2"
Measure the space between your current tire and belt. If it is less than 1/4" the belt and tire may rub. The Kevlar in the belt will eventually wear down the tire sidewall. Added heat from friction may be a concern.
I put a wider rear pulley on my 08 Fatboy. Purchased a chrome one for looks and did not notice in the ad that the new one was a bit wider than the stock pulley. It has been on the Fatboy for about 15,000 miles with no issue.