What I do is what you call shiscabobing the chub. Take a peice of mental fencing wire 6 to 8 inches long and bend one end into a small loop or hook. Usually you would like to have a wire leader on your line. Then take the swivel of the leader hook it to the loop of the wire. Then take the other end of the wire stick it in the chubs mouth and push it lengthwise throught the body of the chub until it comes out the tail. (Your wire for your shiscabober is strong enough to do this) Then pull the leader through to the tail. Then you unhook the shiscabober and hook a trouble hook. The pull the chub back down the line so that the trouble hook is barely sticking out from the tail.
Since you sould be fishing a river it would be wise to have a some wieght a little bit up the line to sit it at the bottom. In my opinion your best bet for big cat is fishing below the dam. The problem with that is the numerous snags. Hope this helps.