my '69 'S' has double pulleys for AC. has a double PS pulley and an extra (triple) groove pulley bolted to the crank. Both are comming off ! I'm thinking of maybe swapping for a single grooved dished P S pump pulley????????????....thanks

 

So are you removing the AC? Look for the code stamped on the pullys. I know the water pump and crank will have a two letter code. That may help others know what you have. I've had the best luck by keeping a set complete and swaping them over as a unit. With the different water pump lengths you may have a pully off just slightly, but off enough to throw the belt. John