Are any of you guys running Powergen Alternators on your Buick Nailhead 401 /425? Very curious what you did for brackets.
The generator bracket for a 57 364 works nicely. You have to use two head bolts that have the extended stud on the right front corner. You may have to slot the bracket for belt alignment depending on the water pump/pulleys being used. Alan Grove also makes a variety of brackets, but they are for alternators.
Depending on which Powergen you use, and mounting location will determine bracketry. Rolling your own may work also. The bracket I listed works fine for a stock size generator, but a fabricated variation of that will work for a shorter unit as long as mounting outboard of the right valve cover is ok.
I've got one you can have, I just have to find it. You do need the head bolts with studs on the end to use it.