They are supposed to stretch. That is how a fastener works. Just like a rubber band. The whole point of torquing a bolt is getting it to the "stretched point,and with cylinder/head expansion, yet not getting to the yield point, which is the point of failure...when the little molecules start letting go of each others hands.
The proper way to stretch a bolt is to measure it static, and then stretched to it proper load specified by the manufacturer. Since this is impossible to do in most cylinder head bolt/stud applications, we use torque value, or torque angle as the Germans like. Either way works fine. The reason you need to lube the threads and especially the under head of the bolt head is to give the best "lab" results of proper stretch for that particular fastner.
Interesting the comitec gasket is looked down on in this application. I have used them on a bunch of FI BMW car engines with excellent results.
Go to ARPs website it is all explained in laymans terms.
I am okay with being a nerd. Also being corrected if I am wrong.
I always understood that the color you see is every other color than the one you see so it is refracted back, all the others are absorbed. :dunno
Good to see more support for MLS gaskets.
There is another thread on site where Vesrah gaskets were condemned. It later transpired that they had been copied by a pirating company, causing Vesrah a tarnished reputation, when their previous track record had been very good. Substandard material quality was the issue.
It is highly possible that the 16V Cometic MLS head gasket failures reported here could be attributed to poor tooling by another pirated attempt.
In my case, the "Vesrah " gasket set I purchased for my 850 did appear genuine in it's packaging appearance. I've moved on, to MLS. I believe that Suzuki may have too!!