Polyurethane bushing squeak

The factory 'knew best' when it came to using rubber bushes in Mopar suspension systems.

If you want to race your car on a race track that does not have potholes/speed bumps etc, by all means use poly.
Rubber bushes [ for the factory ] are only cheaper because of the volume produced, compared to poly.

I've run my cars for YEARS and tens of thousands of miles on the street with poly and Delrin bushings. When properly installed, combined with other high performance parts, and properly maintained they will both outperform and outlast rubber bushings in every suspension location these cars have.

The factory built these cars to be grocery getters for little old lady's, and to be cheap to produce. The performance models were all about advertising, since most of the Mopar "muscle cars" built had /6's. Installing poly and delrin bushings requires additional checks and corrections to factory tolerances that would have dramatically increased costs. You have to consider what the factory built these cars to do, how long they were supposed to last, and what the bottom line was. The factory did not do what was best, they did what would make them the most money. Always. If best handling was what they had in mind, they wouldn't have spec'd negative caster for manual steering cars even with bias ply tires. But that wasn't the goal, easy to drive was the goal, so the manual steering was 24:1 and the factory caster was 0 to -1°. Not because it was best, but because the general public wanted light steering.

You can't just blindly say the factory knew best. They did what they did for very specific reasons, and best handling performance wasn't one of them. And it bears repeating, that was 50+ years ago. Technology has improved, even if what the factory did 50+ years ago was best then (it still wasn't), it wouldn't be "best" now. And it isn't for many applications.

I was a joke son! Or are you that ignorant to see! Grease fittings in the lower pins, Adjustable Struts, so I stated you may want to install grease fittings in the upper bolts because you swear by the lube!!!! for your good buddies , But you just keep writing the book

Sorry, all of your suspension advice is a joke, so it's hard to tell when you think you're being serious.
It really comes down to a personal choice. Can you stand a little extra road noise and vibration? Then great, run poly or delrin. Want it to handle like stock? Fine, use rubber. No need to throw third grader insults at each other for the other's choice. People have run poly bushings for DECADES on Mopars and you don't see problems on a large scale. So, that means either one of two things. Either incorrect installation, or defective parts. Take your pick, but all this childish nonsense with all the name calling adds to none of these discussions. It really needs to stop.

In the end, just run whatever bushings you want to run.

Exactly. It depends on the application, it depends on how the car will be used, and it depends on the other parts in the build. If you're really thinking about it, it depends on who's going to be working on the car, because a lot of the big alignment shops won't mess with aftermarket parts they don't install themselves.

If you want to use all factory parts, poly is not a good choice for your bushings. They require better tolerances than you usually get from all factory parts. If you need to take it to the big name alignment shop on the corner, you might want to stick with rubber and factory stuff. If you're adding aftermarket parts and increasing performance, then poly and delrin is the way to go. But you need to pair them with other aftermarket parts (adjustable strut rods, for example) so you can adjust the tolerances and set everything up nice and tight.