Weird 904 to 408 magnum starter interference issue. Dakota starter won't fit? 64 push button trans. is that the problem?

I just had to do the EXACT grinding on a magnum block last week. Built a magnum based 408, And it WAS bolted to a 904. A 727 may have the starter slightly lower. It took all of 5 minutes maybe.
Yeah, it's a real shame the customer didn't call us sooner. unfortunately the shop really took advantage of him. Sounds like it's common, and if it were sitting right in front of most of us, anyone else would have added some clearance to the block, and maybe a little to the starter, and "starter #1" would have been bolted on, and he'd been on his way. Appreciate the feedback.