Not sure what model DriftAway is, but my '75 32' only has one drain plug, forward below the sole. Mine was iron (!) and I replaced it with a 316 stainless pipe plug from McMaster.com. It was either 1/4" or 3/8", I don't remember.
You might want to check your rudder stocks for leaks, as well as the shaft stuffing boxes (which should leak a little). I also take on a fair amount of fresh rainwater through leaks from the decks and cockpit, still hunting them down.
1975 32' Flybridge Sedan, twin Perkins 6-354 diesels, 1:1.53 velvetdrives, 16 X 19 props. Merritt Island, Florida