What is this crank pulley from?

383Scampman said

thanks for the info , Alan . Looks oddball to me . Never seen a crank pulley with 2 different size sheaves .

Click to expand...

I have... THey use different diameters to for making the pulley and belt move faster or slower...

Just look at a 67 - 69 small block crank pulley with p/s and a/c... They have different diameter grooves for the various belts...