440 balancer

If your engine is a true 69 440 HP it may have the six pack rods which would have been externally balanced and require a unique balancer made for that particular rod/piston combo. The 6-pack balancer will have an elliptical weight on the balancer similar to the cast crank balancer. I would find out what the internals of the engine are first and then you can fit the appropriate balancer to it.