I know this thread is old, but for those who end up here searching for similar info, contact Bomac
Marine in Blairsville Ga. These folks are very knowledgeable about Ford
Lehman engines. They carry
parts and restore the engines, and they are very helpful. I have the same
engine. The guys at Bomac told me today, that they carry all of the
parts for this engine except
fuel injector lines which they can make, and to their knowledge, the parts/service manual is no longer available anywhere.