Umbrella seals are also called valve stem seals, but they are given that name because they are shaped like little tiny umbrellas, shielding the valve guides from a downpour of hot oil. If you have 16 of them (V8 only) they are installed on the intake and exhaust valve stems. If you have only 8 of them (V8 only) they would be installed on the intakes only. You must remove the valve springs to install them.