340 broken at starter side locating ear

If the centering dowl fits in there snug still?????? then i wouldn't worry much about it. if its loose the transmission won't be center and cause all kinds of problems.

missing one bolt is not the problem, the Dowl pin is!

X2 on the dowel! You could still actually use a bolt in the old hole with a big flat washer. See how the dowel fits!!