Tim’s father-in-law purchased these Dualmatic hubs, but Tim’s unsure what vehicle they fit. Given the hub model number is F-230, we believe these were likely used on a Ford truck (possible the F-250, as that was the model of truck his father-in-law had). Anyone recognize them or know if they’d fit on a 1960s/70s Ford truck? The hubs are 19 spline.
As this page from a circa-1970 Brian Chuchua catalog shows, Dualmatic’s the first digit of the hub’s model name was often, but not always, the same as the vehicle manufacturer (C for Chevrolet, I for international, F for Ford, D for Dodge, etc):
Based on the instructions they sound like they are for internally splined hub assemblies like what are on a Dana 44 front axle (and larger Dana axles) from the 60s and onward. Early Dana 44 outer stub shafts are 19-spline.