You will need a V-8 flywheel. Always put in a new clutch. Use a bellhousing from a 55-65 V-8 truck, it uses the angle mounts that should match the crossmember on your 54. In addition the 3 bolt starter to match the bellhousing and flywheel. You did not say what transmission you are going to use. There are clearance issues on the left side between the exhaust manifold and the steering box on pickups. It may not be an issue providing the frame is wider on larger trucks.
You will also need new throttle linkage components to work with the V-8.
Fred
