Overnight Parking near Atlantic City or Jersey Shore

My wife and I are Full-Timers in our 38' Fleetwood Expedition. We just spent last week touring Philly and New York. We are leaving the park we are currently in tomorrow and thinking of going out somewhere on the New Jersey Coast, maybe near Atlantic City to park for the next couple of days before we drive south to D.C. Does anyone have experience with Atlantic City Casinos and RV parking or any recommendations about State Parks or other areas along the coast that might allow overnight parking. Nearly every RV park in the area we have checked are full for the weekend and even if they weren't, we were hoping to go without paying for a park for a few days since next week we are spending the whole week at an RV Park. Thanks in advance for any recommendations.
John.