I put a 393 stroker kit in my 1969 351W and I am looking to get a new harmonic balancer since the old one is all beat up and the rubber is cracking away. I was looking around for a new one and I would like to find out how I am supposed to actually mount the new balancer on my crank. There is what looks like a key way however it looks like this ---. Just 3 seperate dashes in a row. How would I get a key in that? I cant find a way that it would bolt on so I guess I am at a loss as to what I would have to do to get a harmonic balancer installed. Also does anyone know which balancers are better, I am using my engine for a mud truck so I am going to be reving it up a lot and i just want to make sure that I dont slack on the quality so I am willing to spend a little more to get a good one.