Probably 8.8 pounds. I have a 108 listed in this B&H Source Book
https://static.bhphotovideo.com/Fra...ourceBookProPhoto/Section09CameraSupports.pdf as a 3026 so your 168 is probably a 3055.
Same design, same load capacity, different plate for larger camera size.
It looks like you're right.
I measured my 168 and it's 5.5 inches. Though it looks more like the 3026 base it has the 3055 ball upper. Max weight is the same for both @ 8.8lbs so...
That's cutting it close for either of my prime MFC @ 6+lbs or my LFC @ just under 8lbs less the lens, 360 back and viewer attached.
Well that kinda sucks. Kinda... I'm not thrilled about ball heads anyway after using a couple with 35mm. In my humble opinion, they're sloppy. But.. I thought I'd give it one more go.
I suppose if I find a headless center column to fit my Tiltall I could add a leveling plate with it. Maybe use it with my lighter MFs, Yashica Mat 124 or possibly my Graflex 4x5's.
It is sturdy, tighter than my other smaller ball heads... maybe I'll like it after I try it.
My biggest beef with the ball head style is you have to redo all axis once you loosen it. Unlike a conventional head where you can adjust the one axis that's out. Going full 90° easily the only plus side.
But that's me, to each his own.
Worse case scenario I'll sell it if I don't like it.
Anyway... Thank you very much for finding that for me.
And the PDF file link.
Cheers...