Hey Baios, how are you ? Good to see you here. How are things at the G?
Well, I'd say you came to the right place for a conversion question. The G838 guys would kill you for this 
As for your query, the 2C is just marvelous with the original transmission and differentials. I say so because I had a conversion done for a friend on his MUTT.
One thing to note and and alter is the oil sump of the 2C. It makes the engine sit high, so you either put a scoop in the hood or simply fabricate the oil sump in a way that it all sits at the original height.
Unfortunately, hat not come across an Isuzu engine conversion here.
Best,
sarmadq from the G838