Due to a very special order in 2017, or thereabouts, I have a spare set of forged 102mm JE pistons for a 75mm stroke. Soon, I shall send them out with a pair of thousand cylinders for sleeves and fitting of the bores. These were originally made for a TR1 at a 10:1 CR, so I may have the cylinders decked to bring them back up to at least that. I don't see going any higher as: 1) this will be a big motor and heat may well become a problem, 2) shortening them over 1.5mm (six thou) will make the cam chains difficult to tension. Currently, the pistons will run at 8.7:1 in a 920 or thousand and a trifle over 8:1 in an eleven hundred.
This is a long-term project and not bound by my current ideas. As it stands now, I offer just the piston sets for twelve hundred dollars, domestic shipping included. This would require you to sleeve up, plus stripping and boring your cases -- and adding a 75mm stroke crank if you want to run this in a nine twenty or thousand. It can be run on an unmodified 1100 Virago crank; an identical pair is running like this in En Zed. This is without gaskets, oil-cooler, cams, carbs, ignition, pipes, or assembly. All I currently have on hand is the piston sets (and a crank).
Once I have the sleeving done, look for the addition of a pair of big Cometic head gaskets, a complete Athena gasket set, all the engine oil seals in Viton, the pistons sporting ceramic crowns and treated skirts, an XVS1100 crank (over a kilo lighter than the Virago piece) with 5A8 rods and freshly sized plain bearings, new mains, and sleeved-out o-ringed thousand cylinders that have been treated inside and out (the aluminum part only) with a matte black metallic coating (applied similar to both anodizing and powder coating) that substantialy aids cooling. The cost? Sit down. Forty five hundred dollars and your old cylinders. The cost can be negotiated downward with additional parts/work and/or trade for your old, usable parts: engine and cosmetic. You would still need the cases bored to accomodate the bigger sleeves. I asked my go-to machine shop owner what was involved and was told that the cases need to be completely gutted and stripped, down to even all the studs. Then cleaned and bolted securely together with main beaings installed. He remarked on how awkwardly shaped XV cases are then told me eight fifty to a thousand depending how long it takes. Needless to say I was floored. I remembered a quick-and-dirty way to do the cases, but I recommend doing it 'right.' I just reread that page and see that one must modify the procedure a bit to cut out the much larger hole needed.
A last thought before I quit for the day. Since the full kit comes with crank and the nine twenty and larger rods, it should fit and work in all Viragos (and 920Rs) 700 and up. Sorry, it won't work on XVS1100s (V Stars) without a lot of additional parts fabrication. And before I forget: this kit yields a displacement of 1226cc.