Thank you all for the quick and very informative response.  I definitely have a later 59 block, so I need to see if the PO simply replaced the block and used the 'Bird parts or did a complete engine swap.  Time to dig through the parts and see if the water pump has the spacer. I assume the PO used the 'Bird parts as the heads are a 55 casting.  I swear this is the last basket case I buy!  What a pain in the tail!!

FGT1958. Click the link below to see pictures of a used 'Bird crankshaft damper sold earlier this month on eBay.  This one LOOKED good in terms of the location of the 'donut', the apparent condition of the pulley grooves, AND the amount of wear on the snout seal surface. 
NOTE:
- IF someone uses the wrong puller for removal from the crank, the pulley grooves can be bent. 
- Notice the wear on the seal surface of the snout ~ 1 inch from where it enters the timing chain cover.  This groove is not uncommon and is caused by the rubber in the front seal becoming hard due to time and engine heat.  I've seen front seal grooves that were wider and significantly deeper than this one appears.  A stainless steel repair sleeve can be installed to repair the surface.  The  repair sleeve will cost a little over $10 dollars (IF I remember correctly) and should be available at your local parts store.
- $200 is a common price for a used 'Bird damper offered on eBay, although their condition may not appear to be as good as this.
- Although appearing to be in good shape, the donut rubber mount may need to be redone.  As previously mentioned, the repair cost from Damper Doctor with warranty will be in the neighborhood of $300 for the 'Bird unit.

https://www.ebay.com/itm/1955-1956-1957-Ford-Thunderbird-Crankshaft-Harmonic-Balancer-Original-/292279400539?nma=true&si=quqqShIJy3ihW2sUslFtOTwjoaw%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557 

Hope this helps!    


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

It looks like John M no longer sells the Powerbond Dampers and when I checked the price under Ted's part number, you can find retailers that sell them from $300 to $600! Pretty spendy. So one question I have with the Powerbond billet Dampers is; Do they still have a rubber isolation ring or are they soild, one piece units?

Apparently, the coupler sold by YBLOKE for his 471 blower set-up was machined to fit the Powerbond Damper (because they are also made in Australia). So I'm wondering if the spec's on the Powerbond Damper and original Ford Damper are the same?   

  Ron Lane,  Meridian, ID

The Powerbond is meant to be a stock replacement so it does have the rubber isolation ring and original accessory pulleys will mount to it.  If it were one piece, it would not be a damper.  However, that does not mean that it is an exact replica, and you can see from product images that it is not so items designed to fit the Powerbond damper may not fit factory dampers without modification, if care was not taken to ensure that they fit both.  The manufacturer of each item should be able to answer these questions for certain.



Lawrenceville, GA

Summit has the Power Bond damper for less than $250. I have been fighting some tuning issues and tracked it down to a slipped balancer. For what it's worth I wouldn't mess with a used one unless it's been rebuilt. There going to go bad. It may be a week or two years before it happens but it will happen. Also from what ive found Dayton(I think that's the right name) is making the Power Bond damper now.

Durham Missouri

FGT1958.  Here's a couple of used 'Bird dampers presently on eBay, Frank.  Keep in mind that you may need to have any used unit you obtain re-built which will include re-mounting the donut, truing the pulleys, and installing a repair sleeve on the seal surface of the snout.  The cheaper of the two dampers listed already has previously had a repair sleeve installed.

Click the links below to see the dampers presently listed on eBay . . .

https://www.ebay.com/itm/55-57-1957-THUNDERBIRD-ORIGINAL-HARMONIC-BALANCER/263283597260?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

https://www.ebay.com/itm/263295907573?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

Hope this helps!    


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York