Freewheel change

I have a BCD 104 46T installed with the stock freewheel. I thought that would help me get rid of the hamster effect but it didn't. I ordered a 11-28 7 speed freewheel to see if that will help. What will I need to do with the chain. Right now it's about as tight as I dare to make it.
Actually, with the 11-28T freewheel, the two biggest sprockets (1st and 2nd gear) will be the same size as the stock freewheel - the other five sprockets will be smaller than stock. As AHicks says, you should be fine.