The Stovebolt Site Forums The Shop Area Engine Shop 216 engine oil questions

Unless there is another restriction in the oil feed line to the engine, the gauge will read engine pressure as well. Effectively, the oil gauge port is a T-fitting off of the internal oil passage, so the second T just creates a form of manifold. The pressure at the gauge will read the pressure in that manifold, which is the pressure of the oil to the engine parts. If the gauge pressure is too low, reduce the size of the filter restriction and oil pressure will go up. The amount of oil bypassed to the filter will be reduced, so a balance must be found.