Oil pump pressure

Posted by Bill Butterworth On 2012/11/17 0:25:25

1940- 356 engine. Pressure takes 20-30 seconds or so to come up to 40-50lbs at idle.Pressure stays good from then on. Removed oil sending unit to check for flow. Oil Flow coincides with slow pressure build up at start up. Only thing I can of is a blocked screen on the pump. Any other ideas before pulling the pan?
Bill