I also have spent many a day below that dam and my setup is almost the same as yours.When they have that much water coming out of the dam I use up to a 6oz sinker.You drift so fast that a 2 wont keep it deep enough but if the fish are higher in the water you should pull it through them.I was thinking of going with jackson on sat.What has the fishing been like sofar.Its time for the big cats to be stacked up below the dam.If the water is rough below the dam I have caught just as good fish a mile or so down river.Sat will be my first trip this year if we make it.You can buy sinkers of all size at r and r bait shop cheap.Its at the 4way stop on 41 hwy just of the exit.