I've been looking into this as part of a video I'm making about the Steeda sway bar brackets. I haven't been able to 100% confirm anything because my 1993 LX is still in the process of being built, but I have some notes from my experiments that might help...
I put a poly 1 3/8" bushing that came with my Steeda sway bar into a Steeda sway bar bracket (off of the car), then compared the fitment to 15/16" and 1 5/16" Prothane poly bushings in the Steeda bracket (still off of the car). The Prothane bushings fit into the Steeda bracket. The Steeda bushings were a slightly tighter fit. There was no movement with the Prothane bushings, they just slid in easier. I
didn't mount them to the car or onto an OEM sway bar, I was just checking to see if poly bushings for factory Fox sway bars would fit into the Steeda bracket.
The Steeda sway bar has less of a bend where the bushings mount. That could make it difficult for everything to fit together properly. You can see the issue I had with an old 1 3/8" sway bar (with a bend similar to an OEM sway bar) and Steeda Delrin sway bar bushings at the 3:52 mark of this video:
Looking at the OEM sway bar, you might have a similar issue with custom Delrin bushings. I'm going to do more testing in the next couple of months to prove whether or not the Steeda brackets will work with OEM sway bars.