Technically we do not have a balancer. It is just a cast iron balance hub. Years ago I contacted NHRA Div 6 tech director and asked if we (buick guys) needed an sfi balancer. He said if it didn't have an elsatomer sandwiched inertia ring, then no. It is the cast iron inertia ring that fails. So in realty we dont NEED an SFI balancer. HOWEVER.........why not run one to help the engine out a bit. But they only work with-in a certain frequency i.e. RPM, and rarely do we even run our stock block in the RPM range they are "tuned" for. (6000 RPM is typical)
Try arguing with a tech inspector that it isn't a "balancer". Good luck with THAT!!!