Dennie, Due to the wheelbase differences for different coaches you will have to determine the proper amount of adjustments yourself. On my Class C 31 footer I mounted two heavy duty scissor truck jacks in the rear just behind the duals. I used the typical camping trailer screw jacks up front behind the bumper. The main purpose of the front and rear jacks was for stability and not the "coarse" leveling. Initial coarse leveling was done with a complete set of 2x10 leveling planks to get close to true level, then the jacks to sneak up on "perfect".
Use a regular carpenter's level on the kitchen floor to get your coach level the first time and then install your permanent level where you can see it from the driver's seat. Make sure you use the carpenter's level to check left-right and front-back.
Bye the way--hang a warning tag at the driver's station stating: JACKS ARE DOWN. I won't tell you why I know this!