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These engines don't crank over fast and never did even when new. Today, having a weak battery, worn starter or - the biggest problem - too small of battery cables which need to be at least 0 AWG or better 00 AWG. anything smaller will draw too much current and it won't reach the starter.

You did what many people do is to just start throwing parts at it without properly diagnosing the issue as low compression does not automatically mean that it needs new rings. More likely it just needed soaking in oil to free the rings and valve guides so I always recommend removing the plugs and filling the cylinders with oil, leaving it a day or so, cranking it by hand a quarter turn or so, refilling the cylinders, then letting it set another day or so. Repeat as needed for about a week. Once done, remove the plugs, lay a towel down the length to catch the oil, then crank it over to blow it out. In most cases, this will restore full compression even on slightly worn engines.

That said, you're at a point now where it's too late for that so disassembly is needed to check the ring gap, remove any ridge no matter how slight (even a tiny one can break rings) and put on a new head gasket. Olson's Gaskets in Washington State carries them and they are very fast with shipping. Probably honing the valves while your at it won't wort but be sure not to mix them up so as to put them each back where they came from. The shop manual is here as a PDF so best to read through the engine section for details on these things.

Being somewhat dyslexic, I accidentally said to fill the cylinders with lio which autocorrect made into poi! Glad I spotted it as poi would be an odd thing with which to fill cylinders.

A second reason I went with rings was I was seeing blow by while cranking coming from the oil filler tube so it was getting compression into the crankcase as well. The old rings didnt seem to have that much spring to them.

And I did try to free them up with oil and letting them sit for a little while then turning the engine. Its not my first rodeo, I went with what I could see in the numbers and the smoke from the filler tube. Now removing the ridge is not a big issue, I can do that when i pull the head back off.

I get it but blow-by still does not automatically mean new rings on a Packard engine, especially one with relatively low mileage. Unless a ring is actually broken and/or a cylinder is badly scored, stuck intake valves will do the same thing on one of these as the valve chamber is open to the crankcase through its oil return drain holes.

While you have the head off, use a bright light to visually check for cracks in the block between the cylinders and the exhaust values. I rebuilt a several that needed a couple cylinders sleeved and valve seat replaced even though they were otherwise in good condition. They are often hard to see visually but it won't hurt to look while apart.

Since it's been surfaced, check also that there is still valve clearance which will require come clay and time. There are full instructions on other threads, one of which is here for a prewar engine but the same for postwar straight eights too.