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Ok so I had really low compression so I bought a standard set of rings. Swapped them out and now the engine is a lot tighter than before but now the engine turns over so slow I can't really get any compression readings, my oil pressure gauge doesn't really want to show any pressure now either. Has anyone ran into this before? I'm almost tempted to hit the starter with 12 volts to get it to spin the engine fast enough to overcome the tightness and get some oil pressure build up again. When I did the rings I took a wire wheel and cleaned the head gasket and the head and the block surface, maybe I need to get the head surfaced because the gasket looked a little dark between some cylinders. Any other ideas I could look at?

You didn’t replace the head gasket? That’s really a “must” as once it crushes, it stays crushed. Also, with so little clearance as it is between the valves and combustion chamber, I hope they are not hitting. Lots on this site about how to test the clearance but it does involve removing the head again.

What steps did follow to put the new rings in?
Re-using as head gasket is very likely to lead to trouble.
Not reaming any ridge and honing the cylinders is likely to lead to trouble.
Re-using old rod inserts is likely to lead to trouble.
Not carefully checking the condition of the pistons and carefully fitting the new rings is likely to cause trouble.
Mixing parts and not putting used parts back exactly as they were before is certain to cause trouble.
Did you take any pictures?

I was under the assumption that these metal head gaskets can be reused? There was a very small ring ridge, not enough that I was ever worried about when rebuilding other engines. Yes I use the same connecting rod inserts because they looked almost new, did install them with assembly lube to protect them. The cylinders were honed before the pistons went back in to clean the walls. The new rings I got were front grants and look to be nos from the 50s or 60s and have springs behind the oil ring and the second compression ring which seems to be why the fit is so stiff.

No gasket, even solid copper crush gaskets, should ever be reused. For head gaskets, the metal is only on the outside but there is a thin layer of something softer and crushable inside. It was probably once asbestos but not sure what’s being used today.

As for the rings, being in an original box does not necessarily mean that they are the proper size or even NOS. Buying newly manufactured rings is a better way to be assured of getting the proper size.

For the bearings, you need to check them with Plasti-gauge before you can know if they are good or not. These are good, solid and well-built engines but shouldn’t be put together with assumption and guessing.

Another thing to consider with a newly tight engine is the electrical and particularly the condition of the starter motor. Starter could have a lot of mileage and be in need of a rebuild. Worn bushings which are letting the armature drag are another possibility. On a loose engine a starter issue would not be as noticeable as it would be with the sudden added stress of a lot more load. Marginal battery cable size or battery capacity and condition could also be a factor with the added load.

Did you grind your rings to obtain proper gap? .0045"/inch of piston diameter on standard cast aluminum, .006"/per inch of diameter on hypereutectic pistons. Did you lube piston packs when installing?
Battery condition and starting motor performance are important. Replace that headgasket. While the head is off, squirt some oil on top of the pistons, and crank engine and see if it is still cranking hard. If it is....start over, something is wrong.