Alright, so I've taken the flanges off that connect the TYGA pipes to the head. I inspected them to see where they were leaking and the definitive answer is EVERYWHERE that they could possibly leak, they are. That means both pipes were leaking between where the flanges mate with the head and where the flanges go in to the pipe.

So, my plan is to get two grooves machined to fit vitron o-rings between the pipe and flange and use a copper gasket between the flange and head.

I've got some sealant too. I haven't opened it so I can't confirm it isn't orange. It's called Permatex Ultra Copper RTV sealant, apparently it's good for use on turbocharged engines etc. to 700F/371C so should be good except for two things:

1.) It says "Not recommended for use on head gaskets or parts in contact with gasoline". This raises a few red flags as a two stroke exhaust is definitely going to be in contact with gasoline. Seems a bit stupid for something supposedly designed to seal exhausts.
2.) The word RTV is on there. Now, I don't know what RTV is supposed to mean but it was also on the orange crap that didn't do anything other than make a mess. So it this three letter acronym raised more red flags. I decided to wikipedia it. Turns out RTV is an acronym for Return To Vendor. I think that is what I might do.