Hello
Hello,
I would second the last post. Make sure it is not your jackshaft.
I thought that my blower was in need of rebuilding so I had it ported and rebuilt. When I got it back on the car it still made the same sound.
It turned out to be the jackshaft. I replaced the whole bracket with a used one and did not have any more Marbles in my engine bay he he.
Good luck.
Laterz,
D Rainer