ClassicCar

As you all know, double pulleys are getting rare and expensive, but beneficial if you're adding accessories. I credit Superdave with the following idea, which I took to the next level.

Using a Chevy SWP double pulley, I had a local machine shop enlarge the center hole to allow use of the original Hudson crankshaft bolt and washer, drill and tap the 3 mounting holes in the Hudson pulley, shave down the Hudson pulley so the chevy pulley can bottom on it, make a spacer plate, and cut a small relief around the edge of the Hudson pulley to engage the lip on the Chevy pulley for perfect alignment.

The result is a double pulley which can be mounted independently of the harmonic balancer and will not interfere with its function as long as you're careful with the length of the three mounting bolts. The more forward pulley groove is right at 1 13/16 inches from the back edge of the Hudson pulley as is the orginal single groove, so alignment should not be a problem. The diameter of this pulley is obviously larger than original so obviously accessories will spin faster.

The chevy pulley cost me $30 and the machining cost me $50; $80 sounds pretty good to have a double pulley. My local machine shop here in VA kept the specs so if you're interested I can post his name and phone number.