9N8000 Years:1939-52 Temperature Gauge Adapter Pipe. 3 5/8" Long, 1 1/2" O.D; Uses 5/8" -18 UNF Temperature Gauge Lead. Installs In Upper Hose. Cut Hose, Slide New Adapter Pipe In Place, Drill 2" O.D. Hole In Dash To Mount Gauge. Use W/ Gauge #C3NN18287A.