People use dual disk clutched in the Cummins world - for towing. They generally wouldn't be necessary and likely unavailable unless custom built for a 123.

I had an MGB with an extra return spring on the brake pedal that caused problems being too stiff until I found the correct weight spring.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.