HI ALL. I HAVE A QUESTION, WOULD APPRECIATE ANY AND ALL ADVICE. I HAVE A 1973 POLARA CUSTOM COUPE w/360-5.9L. I HAVE READ A COUPLE OF COLUMNS WHERE CAR "GURUS", WERE GIVING ADVICE ABOUT MOTOR OIL AND ADDITIVES IN OLDER CARS. I READ THAT ADDING UP TO A QUART OF 85W GEAR OIL TO THE MOTOR OIL QUIETS THE ENGINE AND ADDS LONGEVITY. ANYBODY TRY THIS? AND WHAT WERE THE RESULTS? THANX. TAKE CARE ALL.