The correct torque spec for the 312 damper to crankshaft bolt would be 85-95 lbs.  That’s the same as the 272/292 engines.  The 1957 Service Manual has the wrong spec listed for the 312 engines.

Lorena, Texas (South of Waco)

This link shows where the search function is hidden

http://forums.y-blocksforever.com/Topic110807.aspx

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South Australia

When I removed mine several years ago the thread was damaged and I originally thought someone had put a metric bolt in there as the pitch was wrong but then worked out it had been stretched.
The specification they give is for a grade5-5/8unf bolt as indicated by the chart in the manual, but the correct bolt is only a grade5-9/16unf so the lower torque specification is correct.
I replaced my damaged bolt with a grade8-9/16 and used a higher torque suitable for that bolt.
http://www.mpi-online.com/technical/torquechart.htm
Here is a torque chart that might be of some interest.

The spec in the Ford shop manual is 130-145 pds. for a 57 312. Seems I remember that is too much and I reset mine (3 years or so ago) according to Tim McMaster's site at 95-100 pds. Is that correct? Also, am I blinded in my old age or is there no "search" function key on this forum?

57 Black Tbird 312/auto