The aluminum part has a plastic locking device inside it. You have to get it hot enough to melt the plastic.Use a propane torch or a burner on a gas stove.
FFR4067, 392W, Vic. Sr. alum. heads, KB 10.2:1, Edel. perf 600CFM, FMS hyd flat tappet, Mallory HyfireVI, FMS stainless shorties, alum. flywheel, Tremec 3550II , 3.73\'s, PowerTrax locker, 15\" PSE GT-40\'s, GM Dark Carmine Red Metallic, no stripes