These Earl's Performance radiator filler necks are CNC-machined and are ready for welding. They come with a 1/4 in. barb overflow fitting attached
Recommended Radiator Caps:
Stant Racing # 10381, or 10382 (Lever Style)
Stant Racing # 10391, 10392, 10393, or 10394 (w/o Lever)
Mr Gasket # 2481 or Domestic ThermoCap