My 1991 z28 has a set of underdrive pulleys (shieves or whatever) on it, however I'm not sure which ones were replaced. I am concerned cause my power steering quits working when my car drops to an idle (After driving the car for a year, I hit a curb because my power steering quit at an inoppertune time. ) Does anyone have the stock pulley diameters (either to where the belt goes or just to the rim) so I can see if it would be possible to replace the power steering pulley with the stock one or something and have it work? Thanks- Jimmy