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