1973 T89 wagon Coolant Pipe 18r-c engine. Where to find a replacement?

Hi new to the forum and first post so bare with me.  I have been rebuilding a 73' t89 wagon for the past year and am finally ready to put the 18rc motor back in but I have been having trouble finding a coolant outlet pipe replacement since mine is too rusty to reuse.  The coolant outlet pipe connects to the heater hose that runs closest to the front of the vehicle.  The pipe itself is six sided and about 3-4 inches long about 1 inch wide and screws into the block just below the head.  It is located below and relatively close to the thermostat outlet pipe.  Anyone know where to find a used or new replacement part? I will post a picture of it as soon as I can.  Cheers