Ran the poly/'thane rear UCA and LCA bushings long enough to not like them. They will reduce articulation (good for a road rig though) and they, unlike OEM, are not a molded, integrated bushing, crush-sleeve and outer sleeve. What happens over time: The 'thane bushing becomes out of round/distorted because of the lack of flex in the material. I probably have photos of mine somewhere ...
For static applications like the steering rack 'thane bushings makes sense; been running mine without issue since the new rack was installed 8-years ago. But for me I prefer OEM bushings for rear UCA and LCA. As always YMMV and just my 2 cents after using them extensively.
So I have been using 80-Series OEM rear UCA and LCA bushings on mine (103k miles on them now) in my custom arms; 18mm bore/mounting bolts. For someone with a lathe you could make 14mm ID/18mm OD crush sleeves to utilize 80-Series OEM bushings yet retain 100-Series M14 bolts if you didn't want to drill out existing mounts to 18mm. I did this a number of years ago for a few guys ... works.