Achcoastal

recently purchased a 1970 cutlass convertible, car has a 1970 455 installed from a 442,E heads rally pack gauges etc. oil pressure is erratic with needle bouncing all over the place. Who makes a correct replacement sending unit for this application... i believe it must be a 0-80 psi range? in the mean time i'm going to tee off the elbow and install an autometer backup oil pressure gauge ...any advice would be welcome thanks

Del70

as you are doing, I would check the engine oil pressure with a different oil gauge/sending unit or better yet a true mechanical oil pressure gauge to rule out any engine oil pressure concerns.