After reading numerous posts on other forums and interjecting what turned out to be false information due to my lack of understanding and my now first hand experience with the HD kit I think a post to clarify the issue might help answer some questions and resolve some misinformation.
Aftermarket 28T pulleys offered by TurboTec and Mainstreet (V-Mod) consist of only the actual pulley. The HD kit consists of a pulley, output flange, shorter belt and assorted nuts and bolts. The difference may not seem significant but read on.
All pulleys consist of 2 basic parts, the 3 point flange that attach's to the transmission output shaft and the actual pulley itself. Here's where the difference comes in. The Harley 28T pulley has a smaller inside diameter thus requiring a smaller flange. The aftermarket pulleys are machined to retain the 30T's inside diameter meaning you can use the flange already installed on the bike. Here's where the major difference in the installation lies.
To install the HD kit you must remove the flange which is press fit onto the output shaft. To do this requires some tools and/or tool fabrication that many of us may not have at our disposal. The 2 major tools are a 30mm thin wall socket (or a thick wall socket ground down to 39.6mm outside diameter) a 3 arm gear puller and some mechanism to prevent the flange from turning as you remove and install the nut which is torqued to 118 ft-lbs.
To install the aftermarket pulleys all that's required is to remove the 3 16mm bolts holding the pulley on and reinstall them with the new pulley.
For those who either do not have the tools at their disposal or are considering switching between pulleys when they plan a long ride the factory kit IS NOT for you. My suggestion would be to buy the aftermarket pulley and if there's an issue with the belt tension buy a belt for the '04 VRSC's.
Average installation time:
Aftermarket = 20 - 30 minutes
HD kit = 45 minutes - ???? depending on tool availability
Thanks for listening