They are stretch bolts and will go into yield if further tighten, no point mate
have you ever reused the headbolts at any time? toyota state that they dont need to be renewen in the workshop manual
Please note you will need to re-tap your block and head to suit. The head must be machined to fit the studs.
can't at the moment, you can get 4AGE and mod to suit though.
stock headbolts are fine in most cases though