I’ve done this before and I would not ever do that again. It will trap the starter in requiring header removal for a starter replacement. BUT……
It required minimal clearance adjustments with a BFH for the steering linkages on my ‘71 Duster. An easy to clearance job. They did fit in pretty darn good for an”B” body header in the “A” body car. For a on the cheap swap, it worked well.
It was very hard to remove them. A Sawzall was the answer and it was still a PIA.