Engine upgrade from 350 TD to 300 TD

Hello, Unfortunately, recently an engine damage has brought my G 350 TD Bj 95 to lie, but at least only at 360k km. Unfortunately, this is not so easy to find a replacement engine, because the market is apparently empty. Now I wonder if it would be possible to take the engine out of the G 300 TD (the one with 177 hp) with not too much effort and install it instead of a 350. Would such a conversion make sense? Does anyone have such a motor conversion already planned and who n yes, how big is the effort and what costs you have to reckon with. Thank you for the help, Yannik.