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

crackedback said
The block likely has some bosses in it that need massaging. I have an 89 360 roller block that a mini and 904 hit the block

The clocking starters can help here too. Never used one

That's possible I suppose. I have had a bunch of magnum blocks and pretty sure i even had a full size starter on one of them and never had to grind anything. New hemi's I have...but haven't seen this on a sb.