The Paxton SN-60 superchargers that were made for Studebaker have serial #'s that start with "MS" for Avanti installations; or "ML" for Lark/Hawk cars. They have only the mounting holes drilled and tapped for the mount for which they were intended. I believe at least the Avanti R2's were painted orange. The one pictured on Ebay has the universal mounting holes, and an "SN" serial #, an Avanti pulley, and is painted black. Somewhere, I have a Paxton price sheet that lists a $20 labor charge to convert an R2 supercharger to an R3. When I first came across it, I thought that would cover painting it red. Maybe they set impeller clearances closer and used heavier springs, too. I think the pulley on the supercharger is the same size, R2 or R3; although a smaller pulley is available after market. The Stude high performance pulley set used a larger crank pulley, to drive the supercharger faster without decreasing belt contact area, like a smaller pulley on the supercharger would. Sometimes rebuilders painted R2 superchargers black. Lots of them were replaced with universal SN-60's. Mike M.
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