Years ago I had my 5.8 at the factory in Santa Ana getting some fiberglass repair work done and had the rear beam replaced as well due to some corrosion where the swivel cleat bed attached to the beam..

They saw what you have set up there on my boat and went nuts... told me there should be equal to no gaps on each side.... I would re-bed and equal out the gap with those as well put some zinc paste on the threads and then goop the dickens out if it with some silicon to prevent water from getting in there... The backing plates are aluminum and SS bolts the will corrode them pretty quick..