ok so im getting an under drive pulley set from a friend Unorthodox 3 piece pulley set and im wondering can i just use the crank pulley rather then all 3 (alternator and idler )? reason being i don't want the under drive cause if my audio system witch i believe to be the alternator pulley. just want a lighter crank pulley but im not aware if all 3 have to be installed in order for it to work.

Thanks in advance

 

the only real different sized pulley in the set IS the crank pulley. the others are just decorative and oem size. So if you don't want everything to be underdriven you need to just buy the OEM sized lightweight pulley. Unorthodox sells both underiven and OEM sized crank pulleys so whatever you get is what will determine that.