Exhaust Head Studs, Getting ready for install of Triad headers Options

[sgetsiv]

This is an awesome forum. Thanks so much to all who contribute.

When I pulled off the 1.7 HE's from the current 2.0 engine, 4 came off nut only, leaving the stud in the head - this I assume is what one would like to have happen, right?

3 of the studs came out without stripping the head. They seem to go back in nice and tight. Is there any sort of thread prep required (grease, loctite, thread sealant) when re-installing the studs? Should the studs that came out be replaced?

Should I attempt to pull out the 4 studs still in the head and replace with new studs?

1 of the studs that came out was actually a bolt with a hex head - pretty sure it is 8mm but I will check carefully. It was stacked with about a 1/2" of washers because it was too long.

Now, I have read most of the posts regarding exhaust head stud issues. But here's a repair technique done by the PO or more likely the previous PO that has not been mentioned (and doubtfully a good idea): the threads must have been stripped in the head and rather than drilling and tapping for 10mm, the hole was filled and a 5mm bolt was used. It was also stacked with washers to get it to the right length.

I am planning to complete the project in about a week, so any guidance would be appreciated. Thanks.

Steve