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

I used a Mr. Goodwrench brand pipe thread sealant when I had iron heads, drain the coolant well below the bolt holes, run a tap thru em, clean and dry them then piled on the sealant and let set a good 24 hours, never had a problem. Was using stainless header bolts from ARP if that matters any. Be sure and wire wheel the present bolts of any rust and old sealants first. Also what pressure radiator cap are you using? is it working like its supposed to, too much pressure and the coolant is gonna find a way out somewhere and or a bad head gasket allowing a pressure build up.