PK numbers

Im trying to ID a trans I have, I know it is a slant 6 727.
is it a lockup or no? Id look at the input and know, but the trans is still in the truck.
where can I look up PK numbers for future reference?
here is the number from the trans in question;
PK4058384 8720 7883
what can be said from this number? how much info on internal guts can be determined from this number? Factory hi stall? or low stall able to be determined from PK?
how high is "hi-stall" and how low is "low stall?

Reason I am asking, is that when cranked, it is sounding like a bad tooth (or more) on ring gear. I haven't had inspection plate off yet but since I had another starter (or 3) laying around I swapped one of my spares in, and same noise. I have a new engine going together for this truck/ and if the ring gear looks like it sounds, once the engine is out, the TC is getting swapped. I have a TC in my sights for what seems like a good deal// but I need to know before someone else buys it, if my trans has L/U or not. if mine is L/U then the converter I am looking at will not work for me.

Runs and drives fine, drives like a non L/U. If it is supposed to be a L/U trans then that "feature" is currently inop.

1 more quick Q, something I don't remember ever seeing before. I had power washed the He11 out of this trans this past summer, while in the truck. Main case took to it well, could not get up onto tailshaft as well as I would have liked. less than 100 mi on truck since the douching of the engine and trans so its still clean.
I have not started the engine in about 3 months, and Im thinking this could be from converter draining back, and will be less of an issue when weather breaks and I am driving it more regular. Does this sound plausible?
The problem here, is that it appears that ATF may be seeping/leaking out threads of front band adjuster.