So here's what I've found out so far...

Pulled the OEM part out of my 1993 T-100 SR5 2WD auto and it's stamped with 26.5 on the part. So I'm guessing 26.5mm. <img src="/forums/images/graemlins/smile.gif" alt="" />

On my 1998 T-100 SR5 extended cab 2WD auto, the OEM part is stamped with 28.6. So I'm guessing 28.6mm.

If you have the regular cab 2WD/4WD (non 1 ton) or a xtra cab 4WD T-100...yer gonna have to git the 27mm part (Energy Suspension #8.5118) and wrap some teflon tape around the sway bar to make up the .5mm difference (if it really matters to you).

If you have the 1 ton regular cab 2WD or xtra cab 2WD, then you git the 28.5mm/1 1/8" part (Energy Suspension #9.5164).