The best gasket to get is a multi-layer steel (MLS a.k.a. "cometic" head 
gasket).  Its the ultimate in durability.  Lots of engines' designs are not 
engineered to properly utilize an MLS gasket reliably and i'm sure when our 2.2 
/ 2.5's were developed, and MLS gasket was not taken into consideration.  
Doesn't mean it won't work though.  It could be coincidental that the design 
will work perfectly fine with it.  I've been asking around various lists to see 
if anyone has put 10's of thousands of miles on an MLS gasket with a 2.2 / 2.5 
but it doesn't seem that anyone has, at least they haven't gotten back to me.  
It takes lots of thermal cycles and miles to finally make one fail... such as a 
daily driver.  IN race applications it'll last seemingly forever.  I'm sure 
that I'll be one of the first to put such miles on one of these if I can get 
this car road-worthy again this spring.
 
Now, more importantly, the machine work to surface the head and block needs to 
be different than what is acceptable for a generic gasket.  There are different 
"smoothnesses" that can be machined into the surface and its measured in AU's 
or something.  I'm fuzzy on that.  The MLS gasket requires a "smoother" surface 
to be installed on.  Say you were to buy a brand new short block and brand new 
head from mopar that has been surfaced.... installing an MLS gasket in that 
setup is not a good idea.  The "rough" surface machined into the head and block 
will literally tear the gasket apart in time.  The same thing happens to 
generic gaskets if installed on too rough of a surface.
 
Both Ford and Chrysler have been using MLS gaskets extensively now.  They say, 
that if a head's surface were to become warped, or scratched, etc you need to 
REPLACE it, not re-machine it.  Its both bogus and true because most machine 
shops (especially back yard ones) are not capable of producing the smooth 
surface necessary for the MLS gasket to slide around properly on and will 
result in gasket failure.  But its bogus in that SOME modern shops CAN 
re-produce the proper surface with the proper equipment and there's no reason 
the head cannot be re-used.  That, and you can re-machine it at the back yard 
machine shop and use an aftermarket composite gasket without troubles.
 
How long will it take for a backyard shops' surfacing techniques to cause an 
MLS gasket to fail?  It could be 5,000 miles could be 50,000.  I don't know.  
Just a little nasty food for thought.
 
 

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