Hi,
I always used leveling blocks that I made for my RV. I used 2X10" boards, so it would be more difficult to drive off the side of the ramp, and they are very stable. With 2X8" wood, you can drive up them, get out and check, then find one tire is 1/3 of the way off the wood, and have to relocate again, what a pain!
I found that by making the top ramp level 9.5" long, and each ramp below 4.5" longer, that the ramps are just right. You have plenty of room to stop at the top ramp (without going over) and usually it works out great! I have 4 level ramps, just because I wanted them, and they fit in my storage compartment. And I have jacks, so I usually do not need them, unless dry camping in a really not level area, or in a Forest service campground near a cliff, where I can get the best views!
I cut the leading edge with a 45 degree angle, and that helps it get up on the next level. I also carry a 20" long board (1 level) because sometimes I only need to raise the left front by 1 level, yet raise the front right by 3 levels, and right rear by 1 or 2 levels. So I might have pulled up on one level in the front, then get out and place all the other ramps next to the respective tires, and then pull up one or two more levels.
It is not required to be within 1" or even 2" of level. The refrigerator can run quite a bit off level. It is more for your comfort while sleeping. But when way off level, the refrigerator will stop working. While driving, you can run the refrigerator - because the movement of the RV will cause all the ammonia water mixture to return to the boiler.
Most class A motorhomes have around a 2,000 - 4,000 pound cargo rating, so a 300 pound jack system is not a problem. I have a friend with a 31' class C and 14,050 pound GVWR. It only had a 1,050 pound cargo rating, including all passengers, food, camping and cooking equipment. Usually they where well over the GVWR when camping. Especially considering they towed a 5,000 pound cargo trailer with a 500 pound hitch weight. My surprise is they bought a class C knowing they owned and would tow the trailer, and it only had a 1,000 pound cargo rating right in the brochure! They tried to return the class C just after buying it, and the dealership would not take it back, or allow them to trade it in on a new class A. They really should have asked more about the GVWR and cargo ratings. I educated myself at great length BEFORE buying my RV.
And my cargo rating is 2,734 pounds. My work phone extension was also 2734!
Have fun camping!
Fred.
