Splitting stands? Man what a luxury. I have split countless tractors over the years and always just used a couple of floor jacks. The only time I bothered with stands was when I was splitting into 3 parts, the engine, the clutch housing, and rear differential, the stands were to hold up the clutch housing section on both ends.
The only advice I can give is that when going back together don't force it. If it doesn't go, something isn't lined up. You can use bolts as a guide but don't use them to pull the halves back together. If you find yourself forcing it take a break, come back and give it another try, if it still doesn't go separate the parts and recheck things then try again.
Brian