RTV900 engine swap from a grasshopper with a D902

Ok, Im new to forum and this is my first post. Recently purchased a 2009 RTV900 that was smoking bad. After further inspection found a hole in the block. I found out that it is very difficult to locate a good D902 engine at a reasonable price!! But I did find a low hour 2012 Grasshopper model 325D mower that has a D902 engine in it.

Here is the information on my RTV900 valve cover tag:
Model= D902-ET03
Engine Displacement = .898L
Family = 9KBXL, 898KCB
ECS = EM
Power = 16.1kw / 3200 rpm

Here is the information on the grasshopper valve cover tag:
Model= D902-ET01
Engine Displacement = .898L
Family = BKBXL, 898KCB
ECS = EM
Power = 18.5kw / 3600 rpm

Notice the difference in the model number extension, the first family group number, and of course the higher power and rpm output.

So the question is of course, will this swap work? Will it be pretty much plug and play? Obviously the electrical connections, and accessories may need to be swapped, but will everything bolt up correctly? The extra power and rpms should be a nice benefit, But will this cause HST issues?

Any help or guidance would be greatly appreciated!

RTV900 engine swap from a grasshopper with a D902