Do you have any idea how much the stretching is (in mm, i prefer)

Maybe it does'nt help you. It might help someone else...

 

This same "tab" idea was on my 323 GTX manifold when I replaced it. I assume it came from Mazda that way so you may be able to order it up from them, but I don't know what the footprint is on the GTX turbo. It's an IHI VJ-14 turbo I think.

 

Come on, the guy on the other topic is adding anti seize to the studs to get them loose after time. It is not a threadlocking stuff.
If you read on, read on good.

Woops I kicked a old topic, anyway, I needed it, I have the problem at the moment. I ordered some stuff on ebay, it is not the red but the blue stuff, hope it will do the threadlock trick:

http://www.benl.ebay.be/itm/40052757...84.m1497.l2649