The Bravo III drives have counter-rotating props so they can run in either direction (like the Volvo Penta drives). This gear set is for a lower unit Bravo III. The gear set in the quote is for a 16/27 ratio.
The ratio of the drive is determined by what mix of upper and lower gear sets you use so there are three different upper gear ratios and four different lower ratios that make up all the drive ratios. On the Bravo I and Bravo IIs they only have one lower unit and the three upper gear ratios make the different ratios.
Hope this helps.