Which Harmonic Balancer/Vibration Dampener to Use (350 SB)
 

As the title states, I'm curious as to which Dampener to use. My current stock one before rebuild was 6 3/4" in diameter, and I've heard some people say a 8" is better. Why? Should I use an 8 inch dampener? Do I have to change anything around if I use an 8 inch? Or should I just stick with stock?

This is just a normal stock bore stock everything motor I'll have in my 70. Nothing crazy for me, just a street cruiser/daily if I choose to pay gas.

Re: Which Harmonic Balancer/Vibration Dampener to Use (350 SB)
 

Just replace it with a quality new balancer of the same size. The larger balancer does a better job of absorbing the vibrations but is not needed on a basically stock setup. To swap it you would need the larger balancer with the correct timing tab for it. If your timing cover has the tab welded on then you would need to swap the timing cover also which involves dropping the oil pan. There is nothing wrong with the small balancer and they are readily available for approximately $75.