[CobraEd]

Tightening header bolts can be an art in-itself. First of all the gaskets tend to compress over time because of the all the extreme hot/cold cycles requiring retightening at least two to three times. Then if the header flange is not exactly straight, you have to torque the $hit out of the bolts to pull it down. All this in conjunction with little tiny soft aluminum threads in the head can spell big trouble.

This is a big reason why I went with the Edelbrock aluminum heads. All bolt holes are helicoiled at the factory which makes the bolt holes incredibly strong. I think If I bought aluminum heads that were not helicoiled, I would drill them and add the helicoils myself while the heads are sitting on the workbench where you can get at them easily. This would head off (no pun intended) any potential problems before they start.

Ed