Note also that I tested the lift pump with pressure from mity vac to the outlet fitting with the inlet plugged. The results were as follows, in order:

At 20 psi, it took about 15 seconds to leak down to 15 psi and held steady.
At 30 psi, it took about 30 second to leak down to 25 and held.
At 30 psi (again), it now held steady with no leak down.
Again at 30 psi, stuck it in a bucket of water and there were NO bubbles = no leaks.

That lift pump would have to be blasting fuel out of the shaft area into the crankcase for it fill it with 8-12 quarts of fuel in a matter of 3 hours total running time (200 miles) since changing/verifying oil level.

I noticed the lift pump shaft does not automatically return to the out-position (such as by spring action) when pressed in. Is it supposed to? I don't understand how it could operate unless the shaft, when pressed in by a cam (I assume) in the IP returns to the out position. Also, the shaft seemed stuck at about 0.5" out (very difficult to move) when I first removed the lift pump. I lubed it and it moves fine now.

__________________
1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]