IIRC you need about three feet on each side, partly for the long axle shaft but also enough room to bend over, kneel down, sit on the floor, and then some room for your work tools. If space is really tight you could first park the vehicle far over to say the driver's side, work on the passenger side and button it up, then move the vehicle over so the passenger side is now close to the opposite wall and work on the driver's side.
I did the math and I think the unconfortable tight working conditions would be a toss up between the cold. If you pulled the rig in with the center line of the hood at 72 inches from driver side wall you would have roon to pull the axle and work In relative comfort. The Passenger side would be tight. Leaving only about 16'' from drive flange to the storrage unit wall. I think you could move the driver side over 1 or 2 Inches to gain a little, and the birfs and axle to some degree can be angled as you pull them and the truck angled as well to make more room then the center line would be 69 or 70 Inches. I could do It when I was young and chuckle about how uncomfortable It was but today with my severely dammaged hands ,NO way. The bottom line Is with the rough measurements I took I believe It can be done and I have lived my life by that conviction, and have paid a Heavy Price for It. I would Offer my shop If you were close or even far and I believe In the character of the Men on this site and I'm sure there Is someone close to you that will help. Be safe and good Luck..!