RE: help
The bore is 28.58 mm or 1.125 in. Is the head gasket the standard "flat ring" that sits in a recess in the head, over a cylinder sleeve?
Some call these cylinder head shims. Is that what you're talking about?
An ASP108 has a 28.50 bore.
An OS 91 Fx &95 AX have a 1.09 in bore.
An OS120 AXhas 1.197 in. bore.