Dad had an 8n. He owned 14 acres and my butt. We bush hogged (yes, close quarters can be interesting), plowed, sub soiled, landscapped, seeded all you ever wanted. IMO as a former operator, it was workhorse.
If you are going to break the case in half to replace a flywheel you are in for some work. We had to do this job to get to the hydraulic pump (its under the seat but there is not enough room for you to do the rebuild through the seat hatch.) Both sides are obviously heavy. DO this where you have a solid level floor. Use cribbing to support the front half. An overhead strap or chain should support the rear with no issue. Rebuild everything while you are there and you will probably never have to go back again. We didn't and it ran on another 15 years without issue.