GSLSEforme

Any time you have exhaust glowing-it is not normal.
You have a seriously out of balance air/fuel ratio,glowing exhaust indicates severely lean running condition with super high temps in combustion chamber.
The engine is pulling air in somewhere other than thru the carburetor= big vacuum leak. Your mixture screws turned so far out and rpm not being able to be adjusted down verifies it.

Have you tried disconnecting vacuum supply hose to brake booster and plugging it to eliminate a defective diaphragm in booster being the cause of problem?

This will be a large leak and should be relatively easy to find...
Do you know how to test for and find a vacuum leak?
When you have the engine running again,spray carb cleaner over top of carb air intake funnel, the rpm will take off and easily double the 1500/1800 idle speed.
The reason why it does so is you are adding fuel proportionate to the amount of air that is being pulled in elsewhere. Again,big leak.
Are you certain the intake manifold doesn’t have any block off plugs missing? Look closely.I worked with another member here that had very similar complaints and that is what the problem was.

Get engine running again,let it idle on its own,and lightly spray carb cleaner around base of carb,intake manifold down to where it attaches to engine and then to each runner on manifold.
When carb cleaner gets close to source of leak,vacuum in manifold will pull it in and raise idle rpm. Try this and post back results.

Ta-Aikah

Hmm. I didn't think about the brake booster diaphragm leaking. The car's brakes when it did run had to have the pedal pushed to the floor to really start stopping, is this a symptom of a bad booster diaphragm?

I'll pull the line to the booster and plug it and see what happens, and try the carb cleaner test. Thanks again!

GSLSEforme

Symptoms of a problem with the booster are a sucking sound heard inside the car from brake pedal and or a hard brake pedal. May or may not be able to hear air wooshing in car. Having to push brake pedal to floor to stop car usually is either a symptom of a problem in brake hydraulics and or brake adjustment problem if drum brake car,possibly combined with very rusty rotors/drums from vehicle sitting for some time. Would be a good idea to take wheels off car and inspect brakes before you can't stop the car. More than one 1st gen got scrapped due to not being able to stop in time. Is the brake fluid you can see in master cylinder reservoir dark in color?

Ta-Aikah

The front brakes need to be rebuilt, I've got the kits to rebuild them. It's just not to that point yet. The previous owner spent a lot of time with the brakes, except for rebuilding the fronts.

The brake fluid is a fresh looking clear-yellow.

GSLSEforme

When you rebuild front calipers,replace the pads-worn or not and have the rotors machined or replace them. Best braking power achieved with a freshly machined rotor surface/new rotor for the new pads to bed into.

Ta-Aikah

I'll keep that in mind, for sure. Probably won't get to tracking a vacuum leak until Sunday, unfortunately.

Ta-Aikah

Sorry for the lack of update.

Finally got around to trying to track down vacuum leaks. Decided to flatten both surfaces of the intake manifold at the carb and at the engine, and use some Permatex Gasket Tack on the gaskets. This fixed some of the vacuum leak issue. Had a much more reasonable AFR at around 13.8-14.

Engine would still die anywhere below 1300-1400 rpms. Vacuum leak still. Got it to run on its own without babying and was going to use some carb cleaner to track the last few leaks down when I noticed both holes/winglets(?) for the upper intake manifold bolts are cracked. One of them looks like it's pretty close to all the way through, and the other is maybe halfway through.

I'm not sure when this happened, but it was definitely recent. The manifold was crack-free when I bought it. I don't think I've ever torqued any of the nuts hard enough to crack those tips off.

What a bummer. Might look around for another used manifold or make friends with someone with a TIG.