If you want an STR legal option for bushings,
Racer's Edge makes them in Delrin. Also waaaaay cheaper than the Elephant parts. I have them in the outer positions only, as it was easier just to swap those. I still have Neatrix rubber on the inners. Fair warning - they
do squeak just a bit, but not nearly as bad as I was expecting. Nothing you can hear while driving, just if you bounce the suspension while the car is parked.
They also make ones for the front, if I knew about them I would have gone with those instead of the polyurethane ones from our host. Not interested in tearing the front end back apart quite yet, though.
I'd also put a nice priority on dialing in some more rear camber, especially with the soft rear torsions. Made a HUGE difference in the rear grip level in my experience.
This is with the 33mm out back, and the factory adjuster maxed out, which was about -1.5° or so on my car. Clearly not an ideal contact patch on the outer rear.
The 33s are 400% as stiff as the OE t-bars, so a softer torsion car is going to have a lot more roll. I went to -3.0° using the CamberMax after that event, and gained a lot of steady state rear grip and much more predictability near the limit. The tradeoff is a bit faster inner than outer tire wear, but not as bad as I expected.
They're a neat product, but if you look
how they work, you can probably accomplish the same thing for free if you have a c-clamp, an appropriately sized piece of shim scrap, and a bit of patience laying around. Free is good.
I'm a big proponent of doing one step at a time when possible, so you can see the results & gains (if any) that each individual product provides. An "all at once" approach is fine, but it's such a shock to the wallet, and you end up having such high expectations for results. In reality, there's a ton of testing & tuning needed to exploit any mod. Having to dial in a bunch at once is much more difficult than the one at a time method.
Good luck, and keep us all posted on what works and what doesn't for you. There's not nearly enough of us autocrossing torsion bar cars.