The stainless is more noble than aluminum, hence the stainless will
corrode the aluminum. But, since the bolt is so small compared to the
mast the damage done by the corrosion will be very, very, very slight
and the damage will not be localized at the hole, but over the entire
volume of the aluminum. At least, that is what I've been told and how
I've done similar work on my mast. Use the goo though.