My harmonic balancer about spun off the engine today throwing my belts off going down the road. I need to order a new one is the 68 429 internal or external balanced or how can you tell? The one that was on it was the stock type.
My 1975 block (engine) is internally balanced or I think it was called zero balanced, not sure. It has a stock flexplate and 1970 (I believe) crank dampener, which probably sells on ebay or a junk yard. It may not hurt to install a Fluidampner, but will cost $$$.