I am wondering if the lower bolts are susposed to be aluminum. That is what I found anyway and they are completely eroded away. I want to replace them with stainless bolts any input?

its for corrosion i would not change them seeing where you live. they have anodes on the end of them.

what I took off was nothing but a carriage bolt made of aluminum. Since reading your input Past Due I have found a set of zinc bolts with anode nuts. But from what you are saying if I am correct it is better to use aluminum in salt water?

i am not sure about the zinc bolts but the ones you took out may be what you should put back in i could check on monday if you want to give me the serial # off the transom plate assy.

they make both them bolts . some have them some dont . i have a formula and a baja. baja has the carrige bolt the fourmula has the better setup