RE: 1.08 equivalent to .91?
As kits if folks like to say ¨theres no replacement for displacement¨ so while you might use a 1.08 and a 91 in the same model they would not be substitutes.
So if you are looking for something with more juice than a 91, I would look for a 1.08 on ebay or here on the marketplace or like FLYER said the 1.20