I would have thought it was imperative to have the flywheel and clutch fitted to balance the engine. Mine is being balanced next week and he needs crank, block, pistons, con rods, flywheel, clutch, and front pulley.
I was afraid of all that. Hoping to keep driving the car until the last minute, so will be trying to get all the parts assembled before starting the rebuild - flywheel, and front pulley. Anybody know if the front balancer of a 94 Disco bears any relation to the P6B unit, if the pulleys are removed?
Technically the harmonic balancer is a damper that is tuned to the crank + attachments. It also relies on the belt driven accessories for some of its damping. So if you are going to the trouble of balancing the engine; you should also ensure the Harmonic Balancer is tuned to the crank. Later balancers had external balance weights welded to them which needs to be removed. Other than that you need to check the belt Vs line up with your accessories.
With regard the original thread, if you are lining up three engines in a row I doubt you really need three full flywheels as there will be plenty of rotating mass in the other two engines to keep things spinning. Also the ZF auto's use a ring gear flywheel which is heavier than a flexplate but lighter than a full flywheel.
94 disco is a bigger engine so even if they look identical the tuning will be different. Mind, on a street car you probably won't notice it...