Before and After

I think best would be direct comparison, like I did with those two covers. Of course, that would be an expensive study...

The 79 has small sump, wide primary chain, small alternator and cover. 1980 onwards mostly large sump, bigger oil eye, alternator deeper, cover with extra oil channel. Both years with ignition sensors in separare housing, mechanical advance with its own drive.
1981 with different ignition, left side cover contains sensors, igniter unique for year 1981. Narrow main chain, different amount of clutch plates 1981 onwards. 82 -83 igniter different, double alternators.
This is off the top of my head, applies to US models. Quite a challenge Stan. Lots of manuals to study.
Good parts drawings at partzilla.com

Would you know about transmissions of the top of your head?

tackelhappy wrote: If there is only two different oil pan volumes , and all clutch covers are the same size, then how is there 3 oil volumes.

The early engines where known to eat cranks - I blew a main bearing and trashed the crank in my 79. Later models were fitted with larger sumps (5.9l) to help alleviate oil issues and I suspect even after that Kawasaki was on a mission to squeeze in more oil - at some point deciding they could safely add another 0.3 litres (total 6.2 l) without causing other problems. Note that they added some oil circuits that weren't there originally - I'm thinking specifically of the pressurized cam chain tensioner. Who knows what else was modified (maybe trapping more oil in the cam galleries) that would have increased oil requirements a bit.

The answer to the riddle of 3 oil capacities for the KZ1300 engines:
Kawasaki made 3 different combinations of oil sump and clutch cover.
1. Shallow sump and 4.6 L marked clutch cover.
2. Shallow sump and 5.3 L marked clutch cover.
3. Deep sump and 6.2 L marked clutch cover.

Details:
1979 through engine # 009426 = Shallow sump, short oil pickup tube (Kawasaki called it an oil filter case P/N 32099-1006. Overall length 6.5 cm), 4.6 L clutch cover with small sight glass P/N 14032-1012. This combination was prone to causing loss of lubrication and resulting engine failure. Upon hard acceleration, especially up a steep incline, oil in the sump would rush to the rear of the sump, and the oil filter case would pickup air instead of oil. The situation was exacerbated by the small sight glass (hard to see the oil level) and excessive oil consumption due to less than efficient sealing of the piston rings.

1980 engine numbers 009427 - 010637 = Shallow sump, short oil filter case P/N 32099-1006, 5.3 L clutch cover with large sight glass P/N 14032-1045, baffle 18020 - 1020. Baffle 18020-1020 is an anti-aeration baffle. It is a sheet steel stamping in the shape of a ring, with the actual anti-aeration baffle at the bottom. The outer circumference of the ring has holes which align with the bolts that hold the clutch cover to the crankcase. It is held in place by the clutch cover bolts. It requires two clutch cover gaskets; one between the baffle and clutch cover and one between the baffle and crankcase. The baffle is necessary because the oil level was increased, but the sump size remains the same. This allows the clutch to spin in the upper level of the sump oil, creating air bubbles in the oil. The baffle prevents the air bubbles from going down into the sump, which would cause aerated oil to be fed to the engine, causing lubrication loss.

1981 and 1982 engine number 010638 and higher = Deep sump, 6.2 L clutch cover with large sight glass P/N 14032-1053, long oil filter case (overall length 9 cm P/N 32099-1017), baffle 18020-1020 through engine number 011195. At engine number 011196, a new version of the baffle was used. It eliminates the ring and is only the baffle proper. To accommodate the new baffle, 2 bosses are cast into the clutch side of the lower crankcase, and drilled and tapped with 6 mm threads. Two 6 mm x 10 pan head screws attach the baffle to the crankcase.

Globemaster - Thanks for your wealth of information here and putting this discussion to bed. Don't know how you figured this out but definitely worth its weight in gold.
I'm going to ask KZQ to add this info to the FAQ page for future reference. It's the anomalies like these that I would prefer to be able to find in the FAQ's rather than searching through thousands of posts.

WELL DONE !!!