Re: Rear Stabalizer jacks
We left the rear stabilizers on when we had the Level-Up installed, and I'm glad we did. The rear Level-Up legs are installed just behind the rear tires...this leaves a long overhang to the tailend of the trailer, which caused a small bit of side-to-side movement at the back of the trailer. The stabilizers take the last little bit of what I call "tail wiggle" out and our unit is rock solid now.
P.S. Just a thought, does your 3370 have hydraulic front legs?..if so I would not remove the JT's. After installing Level-Up we had to add Steadyfast to stop the wobble on the front landing gear....if you have them on the rear electric jacks, I'd leave them there also.