Gets hot and stalls out

Before you get down a rabbit hole you don’t want, get your timing fixed before you do anything else. That’s job 1.

You have plenty of radiator. I suspect your pump is of the standard volume variety so that needs an upgrade.

You also need a high flow thermostat. You can get them from Stewart Components. There aren’t cheap. They are the best. Don’t skimp here.

And then find a set of pulleys that have the water pump pulley is smaller than the crank pulley. That’s huge.

I didn’t read all of what AJ said, but the part about tuning at different engine temperatures is correct. Running the engine over 180 is still a power killer but you have to tune for it.

Hot engines are to save the world from fictitious nonsense. Cool engines make power. Simple as that.

Use the fan you have. I’m not a fan (no pun intended) of clutch fans. What little bit of power the fixed fan eats it is a net gain when you keep the engine temperature down where it should be.

I live in a high desert valley. It gets hot here, not 112 hot but well over 100. I keep my engine at 160. Always.
I've got the timing and IR gun ordered, working on the SS fuel lines, spacer and heat shield now. I'm a very data-driven individual; I'm not fond of a shotgun approach and hoping I got whatever I was going after (to a point: there is some merit to "accuracy by volume", but that's usually more towards full-auto weapons than much else - but I digress). So, I want to get this stuff in, do "before" tests, discuss data, make changes, retest, rinse and repeat as necessary.