Quote:

I think the problem is that the leak is coming from around the heli coil thread not the header bolt. That is going to be a problem as the pipe dope sealant used will continue to erode and remain leaking. I would try a good stop leak first , if that doesn't work then you might have to drill out the coils and screw them back in after cleaning the holes. Use the proper epoxy that will take heat.



Or use a solid threaded insert.


CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax