I own a 72 nova with a basic 350 the oil light started flickering on and off during start off in first. I changed the oil yesterday the car has no oil leaks. The oil pressure stay in the 40 to 55 range at idle and while driving. If I push the clutch in and rev the car the oil light does not flash but when the car has forward momentum it will flash on take off. I figure it is a bad censor where do I look to replace it.. Or do I have a bigger problem?