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

I’ve had this problem with a 400 block. I had to grind the area circled in blue.


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Also had to remove the copper cable attaching piece on a mini starter to make it work with my magnum. I just bolt the solenoid wire and heavy red battery wire straight to the starter now.

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(The oem version of this piece is what I took off the starter)