4.2 Head Torque Error

Without going into detail, I torqued the head nuts on my '67 4.2 to 100 lbs instead of the recommended 60±. The engine has not been run or turned over since the torquing. It was totally rebuilt and bored +.040 6 years ago but has gone fewer than 500 miles. Should I back off the bolts to 60 or… ? Thanks! BigBert

IIRC correctly its supposed to be 52 ft/lbs.

That is WAAAAAAAY over! I would replace the studs and nuts. Both have surely been over-stressed, and are now compromised.

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GEEZ!
Thanks to Ray and Mark both.
Bert

You actually stretched them, but were fortunate enough not to break one. I have broken a few during my puberty while I was growing and getting stronger at the same time.
Since you overdid it by so much, I would replace them. Loosen all of them just a bit and replace one at a time then re-torque.

I’m suspicious of people who don’t like dogs.
But I trust dogs who don’t like people.

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