My engine is internally balanced and I want to use regular V belt pulleys. My only belt driven item is alternator.As long as the engine is externally balanced there will be some sort of "weight" on the balancer.
It may be a bolt on with an aftermkt balancer or cast in as in a stocker.
If you plan to use a light wt hub and bolt on pulleys, another scenario.
I have a set of those same pulleys and that's what I plan to use. Just need to use the short style water pump which is readily available. I'm going fab an alternator bracket for drivers side.Don't know exactly what your looking for but I came across an unusual v belt setup. Late 60's Jeeps and Buick v6 boat engines used a single groove v belt pulley for the alternator. The crank pulley has a very small diameter like an underdrive pulley and the water pump pulley is larger than stock in diameter. They are steel but surpisingly very lightweight. Especially the crank pulley. They were used with the early style short water pump in order to line up. But you would have to fab up the alternator mount down low on the driver side. The marine engine mounts it too low on the driver side and the alternator hits the frame. Jeeps mounted the alternator up on the passenger side head which might be in the way.
I’ve been looking at a lot of the pulley spacers lately and all have balancing holes in them at different points. Some have multiple holes. I’m assuming they are there to balance the rotating assembly at the factory instead of just that part?That's the crank pulley spacer that I was referring to... It hangs off the front of the crank, is heavy, and the factory balance job on it isn't very close.