Thank you both for your further input. I sent a PM to Fred.
I thought the same as Jerry on the engagement. Attached are marked photos that I used to size the shaping of my new pad. I ground the pad to measure near 1/32 more than both measurements with the goal of preventing the pad from preventing reverse to fully engage. I cannot measure a difference between the location of the shift arm with or without the OD locked out. With the OD manually locked out I am confident that reverse does fully engage. When I have reverse engaged then manually unlock the OD, the shifter is immediately knocked out of reverse. That is how I made my stronger spring guess.
1950 GMC 100 Panel Truck, 1958 270, 3-spd Saginaw with BW OD, 3.73 12 Bolt Differential from a 1966 C10, Front Disc Brakes Bought it in pieces 9-1976, driving since 6-1978 Follow in the DITY
