360 Intake manifold bolt misfit

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...

That's great, but the O.P. says he has Eddy heads, and you are telling him to tap them...