The Replacement Lead Leg # LG-177202 and Replacement Follow Leg # LG-177201 are going to be the correct replacements for the VMC900R jacks that are currently on your 2010 Sunnybrook Toy Hauler. These have a maximum capacity of 4,000lbs for each leg.
It may be a good time to replace the Gearbox # LC276602 as well if you did not do that when you installed the new motor. This could have become damaged when the motor became damaged.
The Motor and Switch Kit # LG-217884 is rated for 5,500lbs... view full answer...
As long as the burner is lit on the hot water heater you shouldn't have a problem. If the light is not functioning on the switch then you can double check the 12V power on the back. Assuming you're getting power, it is a problem with the switch itself. For a replacement, you can use the Double-Panel On/Off Switch for Dometic Gas / Electric Combination Water Heaters - White # AT91230. view full answer...
We have exactly what you're looking for! I recommend going with the Karrier ST225/75R15 Radial Trailer Tire - Load Range E # AM10303 which also has that 81 mph Speed Rating M you're needing. You can then pair this with a steel wheel like the Taskmaster Steel Modular Trailer Wheel # 560545WM1 which has the higher weight rating to match this tire and the 5 on 4-1/2" bolt pattern you're needing.
Attached are some review videos for you to check out. view full answer...