1959 ish 261 . Has the full flow button on the engine side. Don’t even ask why I pushed it in…. Well the pushed in button gives full flow out the threaded port for an oil filter. Problem is I’m not ready for that yet. Also my quick fix hydraulic hose port to port is probably too small diameter. As the engine seems to be starving for oil under load. Question . How do I pull the button back out . Thanks