Kanzaki KMP2 vs KMP3

[Asteria]

Hello all
I am in the process of repowering an Island Packet 31 with a newer Yanmar 3gm30f. The newer engine has a Kanzaki KMP2 gearbox 2.61 gear ratio, the engine Im replacing had a Kanzaki KMP3 2.62 gear ratio. The KMP2 gear box is .5 inch shorter so I will need to have a new shaft made up.
My question is; are there any other essential differences between the 2 gearboxes? Is the KMP3 heavier duty? I notice the KMP2 is mostly on the Yanmar 2GM engines.

[Compass790]

Sorry I cant answer your question I'm asking one lol.
I'm assuming the KMP3 can bolt up to the newer engine so can't you use the previous g/box?. Trust its not knackered, the g/box on our old ysm8 is bulletproof, way over-engineered IMO but I'm not an engineer, just comparing its gearbox to motorcycles from my youth it appears to be huge.
Following with interest.

[AA3JY]

https://www.marinedieselbasics.com/kanzaki-marine-gear-manuals/