Bent Push Rob Saga

I googled Denver, and found the elevation there to be 5350.
I checked the Wallace calculator and found that a low-compression (8/1) 73 up 318 should be making ~112psi, so it looks like the valve-timing is good.
But, it looks like 5 of your cylinders appear to be on track, therefore
3 are bad, therefore;
the next move is to do a LeakDown test on those bad cylinders.
and because the one is extremely low; baring having inhaled a foreign object, my guess is that those three have bent valves, which means,
it's valve-job time.
Because of the bent pushrods, I'm blaming it on tight guides, so I'd do both sides; or you could be taking all apart again soon.
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Personal musings; (I gotta say that, else certain individuals will castigate me)
BTW-1
Seized valves occasionally happen to engines that sit unused for long periods of time out in the environment. Especially in environments with large temperature swings and high humidity.
Over the last 55 years, I have had a couple of engines bend valves on me, even now, I have one here.
BTW-2
Because your elevation is so high, you may have noticed that your 318 is pretty sluggish at your current pressure. This is because even tho your current compression ratio may be 8/1, that, because of your elevation, the EFFECTIVE ratio may be as low as 6/1, a full point lower than at sealevel.
Even if you increased the Scr to 9.2, the Effective-CR only comes to 7.1..
At 10.25, the Effective-CR finally gets to 8/1
BTW-3
To get the sealevel pressure back, the Compression Ratio needs to come up to 9.2/1.
and for performance, to at least 10/1,
but not to exceed 10.25 unless you don't mind running 91 gas.
If you decide that you want to bring the compression up closer to 10/1, then I highly recommend to just start with a 360. It costs about the same money to bring the 360 up to pressure, but it will be vastly better at low-rpm. The Wallace points to 51% better, with the 360 at 10/1, versus your current 318
BTW-4
If your Duster has to operate at other elevations, then, you have a problem. You have to limit your cylinder pressure to whatever lowest elevation you will be operating at, which keeps the engine out of detonation; and then, at 5350, it is what it is.
The best solution is supercharging.
But, alloy heads are a reasonable compromise.
With those, you can set the pressure to near 200psi at sealevel, for instance, and the pressure still be near 170 in Denver. Obviously, the 360 thus set up, will be light-years stronger at low-rpm, than the 318, even similarly set up.

Whatever you decide;
Happy HotRodding.