In the past, I have had very good luck finding Vesrah gasket kits at a Parts Unlimited dealer at a snowmobile shop many times , I couldn't find them anywhere else (Top end gasket kit also included the head gasket, not pucks). The only gasket that has failed me with any of their kits have been the pan gaskets on the 500/550 , maybe from lack of use? Perhaps they need to be run more to expand and seal ,don't know, for some reason, but everything else on the 650 s were good. I used an Athena gasket kit on a 550 once, felt cheap to me, like the O rings and other non paper gaskets were made of a different compound that just didn't " feel right" compared to Honda or other makes...did not instill confidence.