Drowning in a cooling nightmare.

I started today on a nice easy t-stat change on my 92' mitsubishi 3000gt and have ended this night in a nightmare. First bad thing to happen was my own dumb fault, I pulled the housing on the top of the engine only to find no t-stat because the stupid thermostat housing is on the side just below it. So I replaced the t-stat and bolted the housing back no problems. However on the upper housing I mentioned the bolts came out roughly and aparently someone had tightened them to much and stripped it slightly. So as is my luck taking them out finished them off. I have tried to rethread the hole with taps to no avail and am pretty close to being out of options other than replacing the bazar peice that both housings among other things are bolted to. Now my next problem is that I have no Idea what that piece is. At first I thought that to be a wierd water pump but I looked at pics of the water pump for this car on the internet and its not what I need. So if anyone can help shed some light on this for my horribly humbled self I would appreciate it. As a side note I am more or less stranded 150 miles from home and have to be at work at 2 on thursday. :banghead:

Helicoils are your friend.
Just make sure you buy the appropriate sized drill for your helicoil set.

Thanks for the tip. Thats a good idea. Luckily it turns out our final attempt at tapping the hole this morning seems to have worked. Should it fail though I will try helicoils out.