I've been doing some very in depth research and have found a few things.
Based on the micro-fiches, these engines are almost identical to the BRP/Can-Am 800 found in the maverick and commander.
The obvious differences i've found with them so far are the clutches and the crank shaft. The BRP crank has a tapered keyed end on the PTO side, and ours have a threaded end on the PTO side.
These engines have identical bore & stroke as the BRP Maverick 800 (as well as their 400 who share the same pistons).
I also found that the BRP Commander/Maverick 800 oil filters are identical.
Fram: 6104
K&N: KN152
HiFlo: HF152
Marshall Distributing: 89-3516
WPS: 12-1796
After my K&N air filter took a turd on me and trashed my engine, I'm looking into replacing the pistons with the Wiseco pistons. Either going with the 40030M09200 (1mm over, make it a 824cc) or the 40030M09300 (2mm over, make it an 842cc). I thought about going with the high compression pistons, but I didnt want to have to mess with race fuel, and I also dont feel like dumping $900 into performance cams.
Ordering them today to see if they will fit. I'll keep ya'll posted.