AC Compressor Head Bolt Size

EDIT: AutoZone carries both types. They were cheap so I ordered both. NAPA calls out the "head bolt" size, but I think they mean the seal plate, as I can see from the photos that the bolt hole sizes are larger on one than the other. The one with larger holes comes also with a paper gasket and a ring of some sort that isn't in the other kit. Can anyone explain where this ring goes? I don't remember it from the last time I changed a front seal. Why would one have the paper gasket and  not the other? See photo.

Note that the description says Santech, but that's the brand of the seal, not the compressor it fits.

The York/CCI manuals say nothing about different seals or seal plates that I can see. I wonder if one type is used in the heavy duty (i.e. semi tractor) or cast iron Tecumsah compressors?

Also,  I solved some of the mystery about the head bolts.  NAPA uses that term on their web site, but they actually mean "bolt heads".  Big difference! The seal plate bolts that have a 1/4" head fit into a 7/32" hole in the plate.

The bolts with a 3/8" head fit into a 9/32 hole.

That explains why I was seeing all these different numbers mentioned on various web sites, but it appears that there are only two sizes, determined by the size of the seal plate bolt heads.  I think our AMCs use the smaller one, but I haven't confirmed that yet.