There are two pipes on bottom radiator tank one is lower radiator hose the other is smaller pipe UNDER the rad hose and leads up under fuel pump into engine block.
after doing some more reading i found a bit more info.
I guess it is for complete draining of the block after draining the radiator. The problem is I bought a new radiator and somehow missed that it had this extra port, so can this be plugged at the engine block? Id rather not have to spend another several hundred for a different radiator