Valve spring longevity ...

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

While looking at HPC's web site (http://www.hpcoatings.com/hpcauto.html) I
saw a section that talked about getting high temp coatings for valve
springs.  They made a pretty shocking statement in there ... that valve
springs are often out of spec withing 40K miles of use.  I must admit that
the only springs I've ever attempted to gauge are WG springs ... ;-) ... has
anyone checked their valve springs on high mileage heads when they get them
rebuilt?  How much degradation is there?

TIA (and IUD)
Steve Buchholz
San Jose, CA (USA)