Try nissanpartszone.com, ebay, or Blue Ridge
Marine in Everett
Washington.
These engines were used in Datsun 720 pickup trucks from 80 to 84 and in forklifts. Let me know if you have more trouble and I will get you the part numbers for the
gasket kit. Then you can search nissanpartszone.com and order them directly without hassle.
Lots of SD22
parts are becoming difficult to find, particularly the
marine specific items.
Good luck.