GM Part# 3899621 Chevy aluminum bell housing. This bell housing fits all 11" clutch big and small block Chevrolet engines with the 168-tooth 14" flywheel. Correct with GM logo and part number! Buyer Beware- there is many reproductions of this bell housing on the market. Most sellers' only state, "correct gm number", but fail to mention the logo is incorrect. These incorrect reproductions come with a CM or CN in place of the GM in front of the part number. This allows a loophole for the sellers to avoid GM licensing fees and inspection standards while depreciating the safety and value of your vehicle, or restoration project. These housings are produced from the GM blueprints. Faces are trued and surfaced. All dimensions are machined to required tolerances. Fits Corvettes, Camaros, Chevelles, and other GM cars, call for questions. Satisfaction guaranteed!