Hello everyone. I have a 74 Nova and I am planning on throwing on a centrifugal supercharger there is only one problem...... I want to keep on a high output 160 amp alternator, unfortunately the 12 Rib belt drive that the supercharger company does not include the extra length for the supercharger and does not offer a 12 Rib alternator pulley. Does anyone happen to know where I can find one or should I call the supercharger company and ask if the have any other belt drive combinations?  

i just downloaded the current alternator parts catalog... they only show up to 8 groove pulleys for delcos alternators with 17mm shafts ...  that is the size of most of them...

big truck alternators might have more grooves  but they will also have larger bore sizes...    you also have to worry about alignment....

volkswagen is starting to supply their alternators with an overrunning clutch to stop the shock of shifting from tearing the belt up... in fact ... supercharger companys are making them for their roots type blowers...

best idea... if the supercharger company will or cannot supply it... is to get one custom made...

there might be too much belt tension for the alternator bearings to withstand...

you will probably be better off running it off a crank sprocket other than the blower belt.....  

That's probably true. OK thanks for all the info.