Originally Posted by Delawhere?

Not sure I completely understand the problem. What I would do is find a CAT scale at a Flying J or other truck stop and weigh the trailer off the truck. Have the front setting on one part of the scale and the wheels on another scale, there are usually 3 sections to the scales. This will tell you what the tongue load is and the total weight of the trailer. Now when you hook back up again you should weigh the truck and trailer combo as a package, this again will show you how much weight you are putting on the rear of the truck but also how much you have lightened the front end of the truck. I usually adjust the spring bars to where it balances out the weight of the tongue over the front and back end of the truck.
Also the trailer should be about level or slightly lower in the front approximetly 1/2 to 1 inch lower. You can park on a fairly level roadway or parking lot and measure the trailer frame and level it front to back. This is about the height of what the ball on the truck should be, before hooking up. When you drop the trailer onto the ball you should be able to pull the truck and trailer up to the 1/2 to 1 inch drop. It also helps to use the tongue jack, mechanical or electric to lift the truck and trailer and take some of the load off while putting on the spring bars.

I don't know how big your RV is but I have never used anything heavier than 1000 LB spring bars in my years of RVing, last RV tow was a 29ft Wilderness. Never bent one so I would be interested in how heavy your rig is. Hope any of this helps with your set up, but remember the people at the RV dealerships usuallly, not always, have people who are experts at hooking up and getting the proper set up for towing that is safe for you as well as the other drivers on the road.
Good luck