Exhaust manifold bolt holes stripped

[Redland1]

If I had to guess it was definitely a bad install due to the way I installed them and you’re going to blow a gasket with what I did lol. The stripped original threads happened when I did the retorque after a week of the install and all the bolts did was turn so I didn’t want to take everything apart and just tapped right through the manifold (critical mistake). The manifold is an oem 870 manifold and the bolts gaskets and spacers were {non-oem}. Helicoil size is M10x1.5. As far as drill depth I wouldn’t be able to tell you right now because u don’t have it apart yet but will in a week from now.

My plan is to use a Big Sert 5015 kit that will keep the M10x1.5 size.