I hate the idea of undampened crankshafts, its so bad for the poor crank and bearings running without one!
If the engine is a hit it and quit it type (one blast pass) drag racing, then get a rebuild after only a couple passes, there MIGHT be benefits to run without a harmonic damper. Other than that, zero reason to NOT have one.
Harmonic balancers are a staple ingredient of any engine build, but what do they really do? Do you have to have one? Is bigger really better? We clear the air about the right balancer to hang on your crankshaft.
Although harmonic balancers are not musical instruments, they do control resonance inside the engine, which is music in some circles. There are three types of engine vibration that engine builders try to minimize. And each type of vibration has a different way of controlling it.
Looks like a diaphragm pressure switch, probably spring loaded, designed to do something with manifold pressure. Its got an electrical spade connector on it, so its likely a pressure switch of some kind.