The valve cover seals go under the hold-down nuts. A minor yet very persistent oil leak often comes from the valve cover nuts. To make matters worse, the oil usually leaks onto the exhaust, getting the whole engine dirty and resulting in that ever present smoke! The best way to remedy the situation is with a pair of longer wearing polyurethane valve cover seals.They may be the last seals you'll ever buy! Fit all A-Series engines.