[BVR421]

I had the same problem with a Jegs mini
about ready to send it back and I started measuring.
It was hitting the ringgear of the new Pioneer flexplate when fully retracted, it needed about an 1/8th". I I measured from back of block to ringgear and then swapped the Pioneer for a factory flexplate and the measurement was a bout 3/16 more so I used the factory flex and the starter cleared by an 1/8th
JJE69, you may want to try another flexplate after you verify that starter is the right one.
2 problems: 1. flexplates can vary the location of the ring gear when they are welded on and 2. the starter guys try to make one starter fit a Pontiac and an Olds both.
BTW, my stock Delco starter fit either flexplate with no issues. It was only after trying the mini that I discovered the difference in flexplates. (quality control issue)