Let's see if we can bring some reason to this thread. Bear in mind I am not looking at your engine.

The exhaust port will be bigger than the inlet ports. The top of the exhaust port will be higher than the top of the inlet ports. You said there were five holes around the liner. There is a possibility that the exhaust port may have a centre bar/web, in which case the openings either side of this bar will be identical. If there is a web and if the engine is ringed this web is to prevent the ring ends from catching the top or bottom of the port. If the engine is not ringed it may be just for strength. The ports in the liner will match the transfer passages and exhaust opening of the crankcase in only one position. Slip the liner in and rotate it until the matchup occurs.

Obviously the piston wrist pin hole must face fore and aft. So that leaves only two ways it can go in. If there is a cutout in the piston skirt the cutout probably faces the front of the engine. Look at the crankpin end of the rod. There may be a chamfer around one end of the crankpin hole. This chamfer probably faces forward. It is to clear the rad where the crankpin meets up with the counterbalance.

What I have described are 'Typicals' I remind you again I am not looking at your engine.

Ed S