Jonn has been working on our 1959 Jensen 541R recently. His notes:
Take complete inlet manifold and carburettor to bench for repair. Remove 3x inlets unions from each inlet runner. Tap out thread carefully to 3/8 unf. Cut 3x bolts to length and fit to each runner with fibre washer and pipe thread sealer applied. Remove each inlet runner from carbs in turn in order to clean and resael vacuum balance pipes between runners. Clean out thoroughly.
Continue with each vacuum connection. Add extra o-ring firstly. Apply sealer and then second o ring and clamp plate. Secure each in turn and reconnect carbs. Remove suction Chambers from each carb in turn. Clean chamber and pistons. Set each jet depth of approx 2 1/2 turns. Use vernier to set each the same, at 1.63mm depth. Refit pistons ensuring lift and return smoothly. Refit each suction chamber and secure.
Refit carbs after John sorted out air leak on inlet manifold.