Wally13, I thought you were still using an X-4, good to hear it has worked well for you. 

I know RAM makes a wider base plate that you can mount to the stock units base.  You may have something different that has been discontinued?
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Previously I was able to adapt a standard round ball base plate by custom drilling 2 new holes and aligning a 3rd existing hole. Aluminum is soft and easy to drill using a drill press.  This accomplishes basically the same thing and is real sturdy. Functionally it works just the same, but I wanted to streamline it a bit and reduce some of the bulkiness and maybe just a bit of weight.  It is a subtle difference, but I think an improvement.
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What inspired me was what RAM had available for the Hook 4/5 units, which basically plugs in and locks the ball into the unit and has a very clean look.  Hook 4 on the right for comparison:

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I have been using a Hook 4 the last couple years, but I think if I wasn't doing a base camping trip, I might opt to go lighter with the X-4.