I built one from a 6" diameter small block V8 damper, with a big block V8 2-groove pulley inverted over it. It requires the balancer hub to be shortened about 1/4" in a lathe, and a corresponding amount of material removed from the outside diameter of the hub where it meets the large diameter part. This allows the hub to be pressed back onto the crankshaft snout far enough to align one of the pulley sheaves with the water pump pulley. The other sheave can be used to drive a power steering pump and/or an air conditioner compressor. The cost of the new parts is about $125.00, plus machining.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!