Tank Stand - Too Small

[darknessheir]

I have a used bathroom sink/cabinet that I am removing the sink from leaving me with a cabnet that is about 18-20 inches deep and 37 inches long, I want to place a 55 gallon talkon top for quarentine and wanted to know if I put a 1/4 to 1/2 piece of plywood spaning the top of the cabinet and extend it 6 or 7 inches over on each side would i need to support that extra wood or would the tank weight be supported by the stand even though it is smaller than the tank!