Off the Shelf 94 mm Pistons by Mike Tiberio
I once ran a set of these in my old SP. They are big bore pistons for VW's and they have the right wrist pin dia, and
compression height for Guzzis. With a 78mm crank, they give 1082cc (1110cc with an 80). I actually used them in a bored out
stock cylinder, I did not bore the case and re-sleeve. I think it ended up giving me a .100" wall thickness. Less than ideal,
but it did work.

http://www.performancedepot.com/pdpartnumber_search.php?compid=99999&partnumber=K001ESV

the basic WISECO part number is K001ESV thats for a set of 4. If you add "-1" to the end, thats the single unit part number.