Yes, you definately require a reservoir.You may have some confusion as to what a leveling valve does based on your statement "I am going to use the leveling valve for the air pressure". It's job is to provide an amount of air to the bag that will maintain a ride heigth and equilize both sides of the axle. When one side is depressed air will flow to that side to increse the heigth. The system pressure is maintained by a regulator and the reservoir will need a relief valve and the lines need a one-way check valve in case of a loss of air. You may be able to get all of that from the f-liner. As you can tell all of them have different functions but it's fairly simple.I don't know about the conventional cab/chassis but I would think they have about the same rear axle setup as the cutaways have. I had a 07' 4500 box van and it rode very well. Surprisingly well in fact. So some of it may be in what your expectations are. Something to consider. The rear springs on the newer trucks are much longer than what your (57'?)LCF was built with. That would be worth investigating if you haven't committed to the air setup. Good Luck regardless and Happy Thanksgiving.
