Help on shortening a Dana 60 truck housing

Well I had a A body 7 1/4” on the ground and for the heck of it I measure to see if the left side was longer the the right and it was. I have the exact measurements in my shop. So if we know the engine is offset the the passenger side about 1 3/8”, it stands to reason the driveshaft tunnel is also? Or am I suffering the effects of the mushroom tea?