The lower idler pully is directly behind the side engine mount. The old pully froze up and is completely gone. Is it OK to drive without the supercharger engaged & how do I replace that pully? .

You can drive as long as you like without the S/C drive, it will just not have boost! Click Here (http://www.automotiveforums.com/vbulletin/showthread.php?t=748619&highlight=idler+pulley) for some more details.