3B, it might be a really good idea to acquire that assembly, as it will give you a spare flywheel to experiment on. I have a former student who runs an auto machine shop, and he does some pretty impressive balancing on race engines. Chances are he could modify one of those big flywheels to work with the 454, as long as he has a starting point. It might be necessary to provide him with a 454 crankshaft and standard shift flywheel as a reference, and have him modify the big one to achieve the same balance after running the original assembly in the balancer. He might even have to modify the bolt circle and/or mounting flange area of the flywheel, but that's not an impossible job. I doubt if you're going to find off-the-shelf parts to make the swap.
Jerry
