Hey does anyone still make Sway bars to get these old boats to corner?
Looking for a set front and rear for my 73 RR clone and a set for my 72 Charger

I haven't looked for a sway bar yet but I will say you should replace the K-frame & Spring isolators with polyurethane or even better, solid mounts.

They did wonders for my cars agility.

You might be interested in looking at what Firm Feel sells:

https://firmfeel.com/collections/1973-1979-b-body?page=1

Concur. Firm Feel is what you want. Be aware the 72 set-up is different from 73 due to the 73 having the ISO (rubber bushings) set-up. BTW I tried the PST poly in my 73 and wasn't impressed and then went the full FF set-up. Took some work (clearancing) but it's obvious and do-able.

'73 B body is going to take a lot of work to make it corner. '72 is a lot easier project. Firm Feel used to make everything you needed for either '72 or '73. Dick retired a few years back so I'm not sure how much they still have these days. Check their website and give them a call.

Tires are your number one factor in cornering. Start there. All suspension tweaks are to help tires do their task.
A sway bar has two primary functions, but with one seldom understood result. First, they try to keep a chassis level during cornering, and two, they attempt to the balance the grip between the front and rear to the drivers liking.
Both of the above are achieved by a SB transferring more cornering load to the outer tire. This additional loading of the outer tire and lowering of the load of the inner tire leads to often less total axle grip. The potential positive offset is sometimes achieved because the tire maintains better contact with the road by not leaning so much when the body rolls. That positive result however is not a given.
I'm also personally a big believer in the racing motto: "Everything effects everything else". and that starts with tires.

Let me add this and take a stab at SB visualization. When a car corners, the outer tire assumes more load than the inner tire. The outer spring compresses, and raises that end of the linked SB. However, the linked SB twists the SB and the inner end of the linked SB also raises, but it is resisted by the inner tires spring somewhat. As the inner spring is compressed, the result is less load on the inner tire, and that less load means there is less force the tire is pushing onto the road surface, and the chassis also has less force to keep it raised. and because of the cornering forces it raises less.
End result, outside tire has more load (grip), inside tire less load(grip), but is not a 1 to 1 ratio, and ultimately there is less total axle grip, but chassis feels flatter in a corner.

Can't speak to the parts availability for your car, but Firm Feel fit and finish is exceptional. I just a 1.25" front sway bar delivered last week. Took about nine weeks to get it. They make them to order.

For the 73 B Body;
Eliminate the Body, Tranny Crossmember and Spring Isolators first.
Firm Feel has the solid mounts for these. That's the only way to go.
I don't care what tires or sway bars you put on it, it you don't eliminate those Iso mounts, you'll still be wig wagging down the road.

OP asked specifically how to make his car "corner". I believe your suggestion on ISO mounts etc more effects "handling", and I believe there is a subtle but important distinction between the two.

How to corner: turn steering wheel in direction of turn
If car continues to move straight, slow down until car makes turn

With any car, it starts at the tires. Tires determine the limit of grip. Suspension is a system that makes the most of the limit of grip in regards to the weight and rigidity of the chassis.
Thus, the next consideration is the chassis. How heavy and stiff the chassis is will determine the rest of the suspension package.

In regards to the 72 B-body, there are multiple choices for this car with Firm Feel and Hotchkis being my favorites. The 73 B-body there is really only Firm Feel. In regards to the late B: The rubber chassis bushings need to be replaced with poly or better yet solid. If you think the 72 b-body has too much road noise, then poly mounts are the choice for you. Otherwise, the main weakness in the 73 B is the front frame rails really having no support other than the very heavy k-member bolted to it.

Your distinction is turd polishing.

In the case of the isolated style suspensions your best improvement for cornering OR handling is replacing those rubber isolator bushings first.

Here's the deal: grippier tires will increase lateral G/speed in corners, but also impart increased loads to the suspension & chassis.
Having the articulating bits firmly located allows those loads to be consistently applied, as in predictable/repeatable handling.
How far the OP wants to take this will dictate the extent of improvement, of course.
But I can offer an example from back in my vintage T/A days:
We restored a privateer Mustang, which had retained a fair amount of rubber bushings.
We also restored the ex-Penske/RWR #1 Javelin, which didn't.
Same race tires, wheels, similar weights and such.
The Mustang was a bit of a pig by comparison, not as predictable/repeatable as the Javelin.

Well, I do not claim to overly knowledgeable in "turds", so I'll stick to SB's and the Op's choice of words, as subtle as they may be.

How much money are you willing to spend?

You could start with my book:

https://www.amazon.com/Mopar-B-Body-Performance-Upgrades-1962-1979/dp/1613252501

This is correct. Look at race cars, they have lots of structure picking up the suspension mounting points for a reason. One doesn't add all that weight to a racecar without a purpose.

Starting simple, tires, eliminating the isolation and shocks are the easiest and highest bang for the buck. Don't forget a solid alignment, meaning not a chain store job.

After that, assess how much farther you want to go.

One could do far worse than looking at say the Big Oly Charger or other vintage NASCAR Mopar.

As the owner of a couple of these "turds" (73-74 B Body) I can assure you that the Iso suspension is a different animal.
If you don't ELIMINATE the Iso bushings, not just replace with new or urethane, you can't go straight down the highway, much less "corner" or "handle."
Keep in mind I'm not talking about control arm bushings or spring shackle bushings.
Chryslers Iso suspension experiment was an attempt to isolate the suspension from the body.
When the bushings isolating the K frame from the body get soft, loose or worn, it can cause the car to self-steer as the steering column is attached to the body, the steering gear is attached to the K frame, and the two are moving independently of each other.
No tires or sway bars can help fix that!

And let's not forget the rubber steering column isolator between the steering column and the steering gear. When that gets old that just adds to the fun!
Then there's the isolator pads between the leaf springs and the differential. When those go soft the diff can move independently of the springs!
And many leaf springs of this vintage have the oval front spring eyes. When those loosen up, you can have rear steering!

I can make one of these turds drive/handle/ride very nicely. As for what it takes to do so...until the OP show me his wallet size it is pointless to contribute.

When you're all done it should look like this

Yes. pointless. Much like your post.