Originally Posted by deniseO30
This makes me wonder if the stainless bolts on my boats prop shaft flanges should be replaced with carbon steel bolts like it had.
Assuming your flanges are carbon steel or cast iron I would use carbon steel bolts. Stainless bolts, particularly passivated, are much more noble than carbon steel. Over time the flanges could corrode under and around the bolts and nuts (unless you used something to isolate them electrically, like Tef-Gel) and the resulting lash will result in damage.
This isn't time critical in my view - just swap back this year. Use an anti-seize compound on the nuts and either lock washers or safety wire. I have a drilling jig for wire holes if you want to borrow it.