Not much in there to limit pump travel other than the seal abutment..........I'm betting on the retaining pin....You continue to push the envelope on the 880 platform.........
Geez..........who woulda thunk it ??I do notice a slight curvature to the pin.Possibly this caused an uneven application of force, concentrating the stress at the weakest point rather than across the entire cross section of the VB pin holes,resulting in the failure??Akin to a prying motion thru the holes....