Ride quality even worse than expected. Advice welcome.

Personally, any person running t bars over an inch is probably applying principles that they wish they could apply to their dick.

I get a kick out of all the stiffening people do to their chassis after they run the biggest t bars and thickest leaves on the market cuz you know....

Bigger is better.

Like maybe the chassis doesn't need to be rock hard and rigid if their suspension on their STREET car has some compliance.

If you don't want a lumber wagon, stop building a lumber wagon.

And yes, I'm ready for the hate. Bring it.

You have to think about it differently. Our cars, although unibody were not very stiff. This is what's these cars feel loose and what makes them rattle and itch. New cars have chassis that are far stiffer than our cars could ever dream about. That stiffening enhances ride quality as it allows the suspension to operate independently of flexing the body. Ever notice new cars have that tight feeling? This is one of the reasons. Stiffening the chassis is a very important first step for updating a 50 yr old car.
As far as the t bars and springs are concerned, our cars were so under spring when new, it's not even funny. Mopar performance themselves even came out with the first updated t bars. Enhancing the roll couple is necessary to drive safely on modern roads. It's the combination where most people miss the mark. This is where you hear about cars that ride poorly or aren't safe to drive.
There are more good parts on the market now than ever. It takes research, money and skills to create something that is truly better than it was new. The bar is very high these days.