I successfully removed the 351M from my 1980 F250 4X4 yesterday. This was the first time I removed an engine, thanks to the info here and in the book by Tom Monroe that I purchased here it went very smoothly. There were a few things that I didn't find here or in the book that might help others:

It wasn't clear where I should connect the lifting chains to the engine. I thought I was going to use the exhaust manifold bolt holes but it looked like the chain would crush the valve covers.
I ended up using the accessory mounting holes on the front and rear of the heads.

I planned on using an engine leveller but they wouldn't fit (I had two different types to use) with the cowl/firewall overhang in the engine compartment. I just ended up using a chain connected from the rear of the passenger side head to the front of the driver side head and connected the hoist hook in the center.

I didn't know what size chain or bolts to use. I ended up buying four feet of 1/4" chain from home depot. The bolts I used were 7/16" course thread and 1-1/2" long. I read that I should use grade 8 bolts but could only find grade 5, they worked just fine.
To bolt the engine to the stand I needed 7/16" course thread and 4 inches long.

I had read that the one piece motor mounts were difficult to remove because the motor couldn't be raised high enough for the lower mount stud to clear the mounting bracket. I had no problem with this, just removed the lower nut and was able to raise the motor/trans high enough to clear the bracket and slide it off the trans. I removed the engine leaving the transmission, transfer case and driveshafts in place.

The only problems I had was breaking 3 of the 4 exhaust pipe to manifold studs. I expected this because the visible part of the studs were rusted away to about half their original size.

I accomplished this working by myself in my driveway. Again, thanks to those who post great info and those who run this forum made it relatively easy to remove my engine.