Heat Exchanger / Cyl Head Stud pulled-

[G69]

Exhaust stud thread repair in these One-Year-Only heads would be straightforward except there are reliefs cast into the 1969 911S heads next to the area that is threaded for the exhaust header/heat exchanger studs.

It sure looks to me that drilling out the remainder of the threads and tapping for for a Heli-Coil insert just might break-out through the super thin wall area where a relief has been cast into the heads-
It can't be seen in this photo but the relief goes IN TOWARDS the threaded hole below the flange and it looks like there isn't much 'meat' there to cut new threads for an insert!

There is a little bit of good thread at the bottom of the hole where some idiot installed a stud too short and it has stripped half its threads.

Has anyone had experience installing a Heli Coil insert in the exhaust stud holes in a 1969 911S head?

Where is the best place to purchase a dozen 8 X 22 Exhaust studs?
The part number 900 061 007 01 doesn't come up on a Pelican or Stoddard search.

Here is a photo to the 911S head- WHAT are these cast reliefs for???

WILL A THREAD INSERT FIT?

Thanks-

[edmayo]

I've had to fix plenty of stripped out exhaust studs, can't say whether I've done a specific 69 S head or not, but they are basically all the same, can't believe yours would be too thin to fix. Go ahead and try what have you got to lose, can't use this way anyhow. Metric studs aren't that hard to find, try Ace hardware.

[G69]

Thanks Ed!

[gled49]

Your lucky it pulled out instead of breaking off. G