Wow. So it’s awesome the problem is gone, but insane it was over a starter.
Yeah, the stud placement is a tad off depending on the bracket. I had 2 brackets both stamped same part number and one needed the hole elongated about 1/8” and the other one worked. But both worked on ac Delco starter.
Also powermaster did an update to the length of the large positive post, the first design needed to be filed a tad on some engines. Did yours?
296-136= 160rpm difference...Did I do the math right- a 217% increase?