BobE wrote:

MS - what vibration damper did you use? 

 
Summit Racing 50 ounce.  It has both three and four bolt pattern.  Fits 289 pulleys perfectly.

MS wrote:

BobE wrote:

MS - what vibration damper did you use? 

 
Summit Racing 50 ounce. It has both three and four bolt pattern. Fits 289 pulleys perfectly.

That 3-bolt-4 bolt crank pully is a God send when trying to find pullies with a non-stock configuration.  I spent a lot of time finding a single groove pully for my 351 with only an alternator. I finally found a 289 3-hole single groove pully.  Fortunately, my new dampner had both bolt patterns.  I don't remember what it is.  When I added power steering, finding new pullies was easy.

 

I have a “Professional Products” balancer with both 3 & 4-bolt holes.  Only issue I had was the paint on the pulley was ‘light’ and some slight rust was forming.  In cleaning it off for re-painting, the painted-on timing marks were rubbing off.  I used a file to make ‘permanent’ timing marks and applied P-Touch labels.  This has lasted for at least 5 years so far.  So, I would stick with Summit unit MS used, looks like much better unit.