You may have a hard time removing the plate on the back of the head, use a 12mm wrench and some high temp silicon to seal the new gasket.I would leave the system in place too.
Good luck and I knowit sucks having to redo gaskets you just did recently. <img src="/forums/images/graemlins/scared.gif" alt="" />
Jeff

It's all good!
83 Shortbed stepside lots of mods
82 Shortbed fully restored
85 Shortbed daily driver
88 4-runner-Wife's daily driver