I bought a dozen old style Duke 850 a couple years ago. Back before the pan tension adjustment was added. I’ve been wanting to modify them and finally got to it. I pretty much copied how Monte Poole modifies them. I got the pans from him. He threw in the stiffeners.

I used a 3/8” fine thread bolt and Nylok for the pan bolt. The tubing is 1/4” black pipe which is just under 3/8”. I drilled the tubes out to accommodate the 3/8 bolt. The brackets for the spring bolts are 3/4x3/4 angle with a notch cut for the frame to sit in. They are tacked in place.

The triangular connector on the back plate gets the swivel out from under the base to make bedding easier. I decided to try the JC Conners shock springs. I have all my wolf traps set up so I can add an earth anchor or extension chain with a 5/16 quick link. I use 5/16 with all my #5 chain and 1/4” with my #3 extension chains so I can tell at a glance what chain I have.