Ok so I found out that I got a good leak coming from the passenger side header. I notice that one of the bolt holes is kinda to big like crazy an the threads are totally stripped out previous owner must of cross threaded moron I'll get pics of it up tomorrow to show everyone. But in the mean time what can I do to finish the prep work before reinstalling it

 

Ok so I saw on another hot rodder formum that I can use a kit called a heli coil kit what are these kits an what do they do I saw that it repairs threads will this way work on my problem that I have on my 350 sbc stock cast iron heads