Coolant leaking from header bolts

[Ornamental]

the problem is sealing the threads not the gaskets , you need to use teflon tape & pipe dope possibly , if there is a helicoil in there it may never seal as the coolant could be leaking between the helicoil & the head not between the bolt

Teflon tape worked me for about a year until I replaced the heads.

[acudanut]

 Don't you have a box of extra bolts (longer type) that might work ?  If your going to the hardware store, get the grade 8.   The last thing you want is a cheap bolt that will just rust and break off.