Help on shortening a Dana 60 truck housing

Although I didn't do the work myself, I sent a 9.25 axle to Moser to have it narrowed. I simply measured the distance from the spot where the axle housing goes into the "center" housing to the outside of the axle flange. Luckily they were exactly the same. I took a total A-Body measurement and had the axles housings cut the same length. Isn't the offset in the center housing and not the axle housing length? Someone correct me if I'm wrong. Worked out well for me. Hope this helps.