I have gone with new Giladorni kits three times and just sent of my S3 jugs to Millennium (Fast Industries) in Canada, I am fitting NOS pistons, rings and gudgeon pin for the Millenium option, only because I want to keep the 750 S3 stock. For what its worth the Giladorni option is less expensive and idiot proof. At a minimum pull the crank out and clean out the sludge trap and then have the crank measured, the non oil filter bikes east cranks and new main bearings and shells, done three and all needed a reground, that and the oil pumps suffer as well from chrome flakes. Once you dive in it can be a minimum of $900 for the Giladorni kits, add gaskets and seals, then seriously consider new valve guides and a head job, another $300 without new valves and springs, then IF you need a regrind on the crank and oversize bearings add another $600 min. An engine overhaul and clutch is starting at $2500 for parts and machining + labor. Is it worth it? I think so, you will have a dependable motor good for another 100,000 miles.