Forest Lovley sent us this article about a lightweight alternator setup:

B & C puts out an 8 amp alternator for the vacuum pump pad on a Lycoming. I came up with what Johnny Cash used to call an "A-dapta-kit" to put the same alternator on a step-up drive for a 220 Continental, or any other radial that has the standard SAE 5 generator mount pad. It's not approved, but I already have a field approval for putting it on the 220 in my QDC. The whole thing weighs 3 pounds installed. If anyone has an interest they can contact me at or phone 952-492-2064 or 952-492-6126.