hi that is because is not alingn properly or it depends if the belt is hanging on the outside u can put a spacer on the pulley of the blower and that will fix it how many psi of boost ur makeing?
__________________ 347stroker mexican block canton main grille,canton wintagetray,canton oil pan,tcy damper,afm b31hr cam,tf heads ported,tf track h. intake.arp head studs,jba headers,frpp lifters,tf rockers tf pushrods,frpp 42lbs injectors,aeromotive fuel p. reg,75 mm tb & egr spacer,centerforce dual friction cluch,3.73 gears,b&m shifter,vortech supercharger @ 14psi of boost snow performance water and methanol injection,afm power pipe,80mm vortech mass air,aluminum radiator,anderson motorsport pms etc etc | 
1993 Mustang notch..Vortec 
