The guinea pig for the swap was our ’84 CJ-7, which received a 4.0L transplant in a previous article. In terms of the engine and transmission, the Jeep is identical to any manual-equipped 4.0l-powered Jeep with an external slave cylinder. The earlier internal-slave manuals are also basically the same as far as the clutch and flywheel are concerned. Though our application is technically a mishmash of parts, the High Inertia Flywheel works with all 4.0L engines from 1991 to 2006. As with many procedures, the first step is to disconnect the battery.