If you don't want to change the location of the alternator, a York to Sanden adapter bolts to the existing mount. It takse some longer bolts and spacers to get the belts to line up. I bought the spacers at Lowes. I had the advantage of having the engine out at the time. Otherwise, working on the Frigi-King and the monster mounting bracket is a pain. Once the Sanden is in place it's somwhat easier.
I think the Mercedes mount was designed by a former tank builder who thought it should be rocket proof.