If that level is below what the POH says, something needs to be done with the engine. There are two numbers that matter, one to the pilot, and one to the A&P. Min safe is going to be less than what the dip stick says. IIRC, on an O-360, you can run one as low as 2 qts before you have to tear down and inspect for engine damage. Personally, I am not taking off with anything less than min on the dip stick. Will the engine probably be fine, yeah, it probably will be. But it's like constantly running you engone low on coolant. It will cause higher oil temps, and eventually lead to a pre-mature failure of something.