Head Bolts and Exhaust Manifold Studs

Glue Man said

That is correct on the 2 different types of threads. Thanks for your help.


I have the head bolts for when I removed the head. It was always my understanding that head bolts were not reusable due to them stretching when they were torqued down. Is this not correct?

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No, torque to yield bolts came into being in the late '70's, and prominence in the '80's, due
mainly to the use of aluminum cyl. heads. The increased expansion of aluminum would
eventually crush the head gaskets to the point they wouldn't be able to recover & hold
a seal. The fix(now combined w/MLS gaskets), was to use longer bolts that were torqued
'til they were floating between elastic & plastic deformation, thus not increasing the load
on the gasket as much w/the high amt. of expansion. The bolts on your slanty can be
used to infinity really, unless they have been damaged,corroded,or over-torqued by an
appreciable amount.