Re-torqueing is a long shot. I hope you don't do any permanent damage. I wouldn't re-torque myself, but what the heck do I know? If you do end up having to replace the head gasket take a look here:

http://www.peachparts.com/shopforum/showthread.php?p=538878

http://www.peachparts.com/shopforum/showthread.php?p=194343

http://www.peachparts.com/Wikka/M104HeadGasket

Good luck!