Gen3 LS1 head bolt threads in block pulling

[Gareth]

It seems wurth stock them

[VX L67 Getrag]

Thanks very much for the offer Biggvl, pm sent & again appreciate the offer!

[VX L67 Getrag]

BIG thank you to Biggvl, the thread sert tool worked well & easy with a bit of modding while in engine bay too!

I now have a new drama with my brothers car since I put it back together with thread serts (not that they have anything to do with issue) it had the tri-metal head gaskets & I don't like using them if there's carbon option if both surfaces haven't been properly machined.
So I found a material based Felpro head gasket & used them instead & all fine except once you drive the car for more than 10 minutes (can drive for hours & temp gauge sit's steady at 1/2) but then switch the car off it bubbles in the header tank?

I can't imagine the gaskets would cause this seeing it doesn't leak or overheat, but it's the only thing that I changed the type of what was on it.

[immortality]

Pressure cap showing its age?

Did the gaskets have all the same holes?

[VX L67 Getrag]

Yeah rad cap was going to be the first thing I changed, but I'm not 100% sure about ALL the holes in gaskets & kicking myself for not checking now!