The new production of cylinder is made 2 mm shorter than before, so the height is 91 mm.
That will make it fit to piston 3965, on this piston is the piston pin 24 mm from the top, the bore is made 54.025 as a minimum diameter, because the smallest piston is 53,965 mm., the advantaged with the new piston 3965 is the weight is 11 gram lighter than 395
You can also use piston 395 or 396 if you use the 2 mm thick aluminum gasket, you can see on the photo,
If you use the new shorter type of cylinder, then you have to change the exhaust socket or cut of 2 mm. in the bottom as you can see on the photo.