Hello, gentlemen. Newbie question, probably, but I'm a bit confused here. Which set of gears in a Volvo-Penta 280 changes the gear ratios? I have an outdrive with straight six gears, need the 1.61:1 v-8 gears. I was under the impression it was the upper set of gears, but now I am seeing lower units advertised as 1.61:1, and could use the entire lower drive, as mine has a broken lower fin. Any help here would be highly appreciated.