Concentrate on the brackets. Aluminum pulleys do not wear well.

Tubo

I was thinking about doing the same.  I unfortunately don't have anything to machine the brackets. I was looking to mock something up using wood as a template then when I got what I wanted find someone to machine the brackets out of some 6061 aluminum.

I planned to use some metal original serpentine pulleys. i already have the sanden compressor and a late modek 130 amp 3g alternator with serp pulley.

If you come up with something I would be interested in having you machine me a set or get a copy of your template.

 

Have you ever priced a stick of heat treated aluminum bar stock?  The crank pulley would take at least a 6" diameter chunk of round barstock.  A quick look at an online metal supplier shows $175 per foot for a 6" diameter piece.  I'm sure you could get it cheaper loally or if you bought larger quantities, but making pulleys is a ver expensive proposition.  A crank pulley, with the offset it has, will take up almost 6" of that bar.  And Tubo is correct, they do wear out very quickly.  I have gone through two and am now on my third crank pulley from March.  A friend works at a not-to-be-disclosed oilfield equipment manufacturing facility and machined his pulleys in the prototype shop out of 17-4PH steel.  Now THOSE will NEVER wear out!

I would prefer mine out of stainless but that is for when I win the lottery....