-original 1/2 x 14 N.P.T.F.-, V8, Chevrolet 305 & 350 C.I., with factory gauges/Rally Gauges... see more-original 1/2 x 14 N.P.T.F.-, V8, Chevrolet 305 & 350 C.I., with factory gauges/Rally Gauges (correct resistance and connection, produces accurate gauge display)