Anyone know which are the drives equiped with from Merc?
Part #'s are the same between the 2, except for the suffix which is not on the zincs.

Use magnesium for fresh water and zinc for salt water, the difference in the part number will be seen in the price. Magnesium will cost you about 3X's more then zinc does.

Yes, I know the use of which, just don't know which Merc puts on them when they ship a drive/transom assembly out the door.

I have read where there is really no longer 'zinc', but are either AL or Mag. Just what I read on a merc site.

Just a thought, and probably a not so smart one, but if you drilled a small starter hole into the zinc and collected all the shavings, then applied a torch to the shavings, aluminum will melt to a puddle, magnesium will burn white hot. Keep in mind safety because nothing will extinguish the fire, it will burn underwater. Only use a small amount of shavings.

I believe Merc uses aluminum anodes on new drives as they have no idea of intended usage of the drive. The AL anodes will protect in both salt and fresh. Although, my personal experience is that AL is not worth much protection in fresh water. 4 months in the water and they hardly corroded at all. I use Magnesium in fresh and man they corrode like crazy in the same time period with no to very little corrosion on the drive.