Wheel base on Class C

Ratio-wise, that should be OK. Much longer and you'll overload the FRONT axle. The problem usually is that the WB is too short, front way underloaded for decent handling, and rear ends up overloaded. Longest WB I've seen on a Class C (not a Super C on medium truck chassis, ordinary C on E-450) is 223". Ours is 218 and we have around 4600 on the front. 220 should be fine, but still a good idea to weigh the coach and see where weight actually falls.
Glad to see the slides on opposite sides. Should help the left/right weight distribution.