When porting exhaust side of the head what is used to "plug" thermactor opening? The thermactor bump near the valve is drilled open and at the back of the head the port is closed shut. Im aware that it needs to be massaged alot but ill have an opening just sittin there when i cut it down some wont i? Do i tack weld once shortened towards the end and then finish port? Also i need recommendations on a good set of exhaust gaskets. Thanks for the ongoing help with my build!