Here are a few pics. I have removed some material, but I do not know if the head is solid in this area, or has a water jacket or hollow area to be careful with how deep to grind .
I have to wonder WTF they would cast those heads like that? That's a pretty small base distributor. I agree with y/r. It might be best to call Bruce. I would "guess" you'd be ok to grind clearance, but who really knows? Thanks for adding the pictures.
