QUOTE(ctc911ctc @ Feb 24 2020, 08:38 AM)
********UPDATE********
Took the manifold off - cannot believe how easy things are with the QuickJack!
Seems that the hole has threads - cannot figure out of those are inserts or the original threads??????? Seems that there are 7 good threads, dirty but solid.
How deep are these holes supposed to be?
Also, how damaged is the valve from running hot?
Where do i order the studs?
Click to view attachmentLong shot of the hole and valve
Click to view attachmentAngle shot to show threads
Click to view attachmentStraight shot - does the hole for the stud go into the exhaust gas chamber? Clean out the hole?
You need to run a 8mm tap into it and see what thread is left,not looking good in that pic,I have used a stepped stud before which is 10mm into the head then 8mm on the other end,there is enough material in the thread boss to hold them.
You will need to get this stud made unless you have your own lathe or someone you know has one,or go for a thread insert ,I prefer the stepped stud as it holds on really well due to the larger thread (10x1.5mm) and is a permanant repair.
Thread inserts/heli-coils are great but I don't like them used on an exhaust stud repairs.