Lucked out maybe
 

Was at the swap meet today and was just looking for a few little items. Found this engine crank double grove pulley new in a GM box (NOS) GM Part # 3955291-AB. Asked the guy what it went to and he said a big block chevy. Had no idea if it was for my car and bought it any way. Turns out it really not correct for my car but is for a L78 engine, or LS6 car. Got it for a great price, so I check around tonight and it looks like it is rare, especially in new condition. Here's what a used one sold for.

http://www.ebay.com/itm/1969-70-CHEV...-/250874611261

Nice find, some people just don't know what they have.

You can pm me the price you paid.I gave $175 for a correct used one for my car.

Sweet......