JD has exclusive parts supply for any Kawasaki engine used on their equipment. May be other brands also but they are standard Kawasaki parts used on their other engines, but you will not find a spec number from Kawasaki used on JD equipment.
Plain BS. I have no problem looking up the JD Kawasaki engines. You just don't know where to look which is what JD wants you to fall for. Only a very few parts are not available from Kawasaki. Most Kawasaki engines I repair are on JD equipment and I don't buy the parts from JD. Matter of fact I got a Kawasaki fuel pump and carburetor parts coming in Wednesday for the FD440-AS00 on the JD LX178 from my Kawasaki distributor.
I got the head and valves for the FH661V-AS04 engine on the 737 I repaired a few weeks ago. JD wanted $226.91 for it but I got it through my distributor for $174 So I actually sold the head to customer for $195. Made a decent profit and saved the customer money too. Of course there were valves, stems seals, and gaskets are not part of the $195 but I pass along similar savings to customer.
Then of there was the FH601V-FS14, FX730-AS20, and PA540A-BS02 eariler this year that I also got parts for from Kawasaki.
OP, No problem here looking up that engine. Can you put together a list of parts you are wanting?, and I can get the Kawasaki PNs for you. I know you need the head gasket, crankcase cover gasket (oil pan) and the two crankshaft oil seals but what else are you wanting? Are you actually wantng the crankshaft, rod, and piston?