If the balancer were fine I'd be the first to tell you, but it is not. The two metal pieces and the rubber are bonded together at the factory. If the rubber joint is disturbed it is no longer a sound joint, and it would be a miracle if that outer ring didn't slip. Best case, the slippage would just cause the engine to be severely out of balance. More likely, the outer ring will "escape". When these things come apart at speed it is often not a pretty sight. If you're lucky, all you lose is a little sheet metal.
This guy was lucky. It went out the bottom in one piece:
https://www.youtube.com/watch?v=EAM6povsqno
...and some horror stories:
https://www.jalopyjournal.com/forum/...cident.390518/
Don't just trust me. Wait for others to offer their experiences. I'd love to be wrong on this one to save you a little money, but unfortunately, that money will be well-spent.
Good luck on the build!