I am looking for a new tripod head. I just bought a beautiful cobalt blue 501CM kit, and I also just bought a toyo 45CX large format camera. Due to the size and weight of the 4x5, I need to buy a new tripod head. I have decided to get a Really Right Stuff ballhead that takes arca swiss plates. I am wondering if the standard plate which came on the base of my 501 will also fit a standard arca swiss cl&. Ideally it would, but I do not belive this is true. I need to know if the only way to get my 501 onto an arca swiss cl& is to attach an arca swiss plate to the standard plate on the bottom of my 501. This seems redundant. Any information or suggestions would be greatly appreciated. Thanks. David