Header Bolt Battle

[LGAFF]

Picking up from my last battle with a Mobile 1 oil filter....I am in the midst of a header install.....as the motor was pulled and rebuilt once, apparently the tech that did the headers must have mistaken the head torque specs with the head(er)......Several of these have taken a cheater to get them to move...having high miles the corrosion does not help.

Needless to say there was one bolt that decided it did not wish to depart. The bolt head rounded off when I used the cheater. Heat, bolt extractor socket, etc has not worked. Wondering if the next step is to get an angle grinder to either 1)cut off the bolt head 2)cut the bolt spacer to relieve some of the pressure. Its at least one of the easier bolts to get to.