360 Intake manifold bolt misfit

Now, that would be a huge mistake! The Eddy heads have heli-coils in all the threaded holes. You never tap a heli-coil.

I run stock heads, not Eddy...

If he's galled the threads by trying to put them in and they get tight before reaching clamp load, then they may need to be "freshened up"...

Damaged threads will not give proper torque or clamp load...