I ran into the same problem with the dealers, 120 bucks for the whole assembly. I tried a few machine shops for the bolt but nobody has a left hand thread that fits the pulley. Looking at the pulley assembly, I don't see why the thread has to be left handed if there is a locking nut on th eback of the pulley. Im' thinking of drilling out the tensioner and retapping it with a standard bolt. I'll let you know if it works. I see you point about the bump steering with larger wheels, I stil have the stock 16's with factory size tires but I will probably have the same problem as you if I go bigger.

95 GS
-99 front end conversion w/projectors
-aem cold air
-pacesetter header
-apexi dunk cat back
-energy susp. bushings and sway bars
-kyb gr-2's
-weapon cRap coilovers (replacing)
-frt/rear strut bars
-camber kit
-97 gs rims with mich. pilots

jeff_TX

95 GS
-99 front end conversion w/projectors
-aem cold air
-pacesetter header
-apexi dunk cat back
-energy susp. bushings and sway bars
-kyb gr-2's
-weapon cRap coilovers (replacing)
-frt/rear strut bars
-camber kit
-97 gs rims with m