TR6 - Manifold Vaccuum

[Bud_Rolofson@nps.gov (Bud Rolofson)]

Does anyone know what the intake manifold vacuum pressure should be on a TR6?  

I'm getting a reading of 17 Hg at 5280 ft which corrected for altitude would be
a little over 22 Hg at sea level.  Is that a "normal" reading?  I tried looking
in Bentley and couldn't find a spec. for vacuum

Thanks
Bud 71TR6 CC57365