Deeper oil pans:
The first 1300’s reportedly had oil starvation issues:
Globemaster reported: The reason Kawaski changed to the deeper oil sump was to eliminate oil starvation. With the shallow pan, hard acceleration, especially uphill, resulted in the oil flowing to the rear of the sump. The oil pickup would then draw in air. The result was ruined main and rod bearings. Engines that suffered from this would be full of metal shavings.
Kawasaki’s solution was to fit a deeper oil pan and a longer pick up tube that reached more deeply into the sump. The Kawasaki part number for the deeper oil pan is: “XXXXX-XXXX”. The part number for the longer pick up tube is 32099-1017.
The difference between the earlier 4.5 liter sump and the later 6.3 liter pan is obvious as the earlier pans had the drain plug facing forward while the later, deeper pans had a drain plug that faced down. The later pan is 1 ½” to 2” deeper with enough added capacity to hold almost two liters of oil.
The larger oil pans were fitted to 1300s starting with the ’81 KZ1300-B2 or any of the 1300 Voyagers. The larger oil pans from the Voyagers are different than the larger KZ pans and it’s been reported that they will conflict with the stock KZ exhaust system.
To reiterate: There are 3 different pans used on the 1300 engines. The 79' and 80' shallow pan; some 80' B2 models had deep pans and all 81' and 82' model KZ1300's as far as I know came originally with deep pans; and all ZN1300 Voyagers had a deep pan but it's slightly different than the KZ pan. Even though the Voyager pan will bolt on to the KZ motor and we can use it in that sense, it will interfere with the stock exhaust. But then again, how many of us still have stock exhaust?
Here’s a link to a thread discussing oil pans:
https://www.kz1300.com/forum/engines/4285-oil-pan-swap?start=0