Spectre 9774; Performance Mass Air Flow Couplers
This kit comes with one 3.625 in. to 4.000 in. and two 3.875 in. to 4.000 in. reducers. It adapts most boot-in style GM mass airflow sensors to a 4.000 in. intake system.
K&N; Neoprene Gasket for Mass Air Flow
Mass air flow gasket for GM Vehicles. K & N part # 09033