Can't get these damn headers to stop leaking COOLANT!!

I'm so pissed off at this point, I am about ready to take these damn tti headers off and install manifolds with studs in the head. I have tried everything I can think of to try and seal these damn things up but it's not happenin. What do you guys recommend to put on the header bolts to keep them from pissing coolant? I have tried liquid teflon "didn't work at all" and black silicone "works better but still sucks". It's a 440 by the way. HELP PLEASE!
Get some good old pipe thread sealent...I built a 440 that had heads with every bolt entering the water jackets...all of the plumbers have been using it on boilers to seal pipe threads for a long time....



you don't have to let it dry or anything...heat it up right away with all the pressure you want....coat the threads of the bolts real good...insert and tighten them up....no worries