[rswyan]

I used a piece of 2" x 6" cold rolled steel for the pivot pin. Image shows the pivot pin welded to the angle adjustment pin plate and ready to be welded to the tine holder.

I drilled a 2" hole in the angle pin adjustment plate and then welded the pin on the bottom side (slightly recessed) This in turn, was welded to a piece of 4" x 4" angle which will be welded to the tine holder. I drilled a 1 1/32" hole (biggest S & D bit I had) in 4" x 4" angle so that I could weld the 4" x 4" angle directly to the pin, as well as welding it on the sides to the angle pin adjustment plate.