How about just keep trying to get it running and work the air out of it.
Precisely what I ended up doing. After standing there confused for awhile, I thought, "hey, why not force feed this pump?" and so I grabbed one of the raptors we have lying around the shop and fed it diesel straight from the can at the lowest psi the raptor can do (should be around 7-10 I think). Anyway it fired right up but not in the nice, steady idle way that it used to but with much drama and clattering and sturm und drang.
So now, it starts right up but idles at, if I had to guess, between 1500-2000 rpms and throttle input does absolutely nothing. There was an actual pile of soot behind the exhaust after this drama. Okay so, my thoughts are this:
-Is the feed pump somehow throwing stuff off? I'll check tomorrow when I try to run it off the tank in the car (ran out of time tonight).
-Did I somehow slip the belt on the crank pulley when putting the new pump on? The pump and cam are lined up as they should be, but I didn't check the crank figuring that it would be unlikely to move as I was working up top. Again, something I'll check tomorrow.
-I noticed that the anti-tamper collar on the max-fuel screw is missing from this pump; though it ran fine on the previous car, is it possible I need to pull back the fueling or something?
-Is the pump in need of serious advance or retard?
Like I said, experimentation will continue tomorrow. Thanks to y'all for being a springboard upon which I may bounce ideas.