Copper gaskets didn't work for me either, man I think I've tried everything now. The copper silicone and 'paper' gaskets have offered the best I've seen to date, but still I got ONE last port that just won't hold.
Looking at the science of these Remflex gaskets they sound really good! High carbon content, extreme heat range (3000 degrees) and good compressibility. By golly these just might be the ticket! I didn't check the price and don't care. If they work, their priceless.
I'm ordering a set through NAPA on the Big Island, apparently there not available on Oahu.