273 Harmonic Balancer Type???

Plain Jane 273-318-340. The only thing different is that some early models have the timing marks reversed on the timing cover (right hand side vs. left hand side) for water pump. You can find TDC and make new marks if this is your case. Any new or good used harmonic balancer will work on your engine. Unless you are racing or high RPM usage...no need for the Fluid or other high dollar piece.