This super high-quality W-25 OAI air cleaner top assembly has the proper vacuum valve, air filter top, vacuum lines, flapper door, springs and valve cover spring retainers. They even come with an air filter and the assembly will work on 350 and 455 OAI-equipped engines having a four-barrel Q-jet carburetor. When converting to OAI all you have to do to seal the assembly to the hood is use your original four-barrel air cleaner base and install the valve cover spring retainers and hold-down springs. There is a difference between the 350 and 455 OAI assemblies with the 350 versions having a 3/8" taller foam hood seal. Get the factory-correct look along with horsepower and torque using this outstanding reproduction W-25 OAI air cleaner top assembly.