While reattatching my thermostat housing last night, I managed to pull the threads right out of the intake. After I finished cussing at my self and every first born on the planet, I picked up a Helicoil kit. The problem here lies in the fact that I've never done this before. It looks very straight forward. However, the part that's confusing me is that the instructions say I'm supposed to punch out the notch on the bottom to keep it in place and to take off the tab. The problem I see is, how does one go about this when you can't actually get to the back side of the hole?

 

Reach through the hole with needle-nose pliers and break it off. (Twist back and forth). Make sure the last of the heli-coil threads is just below the surface of the intake before you remove the tang.

 

Had to do it on an alum TPI intake and left the lower tab in place since it was a blind tap but cut it to size before install

 

use a drift punch. that tab is there to allow you to screw the threads in. once in place you wont need that tab and need to get rid of it so the bolt can pass thru. you did put some epoxy or thread lock on the threads before installing i hope

best thing to remember is once the helicoil is in place...its stonger then when new

 

I haven't put it in yet, but I've got some red locktite. I'm assuming I want to let it set before using the bolt hole for real.

 

Just put a screw driver in the hole on the tab and give it a good tap with a hammer and it pop's off. They are made to do this. Easiest part of the job.

 

A lot of sets come with a punch to do this (it's just a rod that passes through the fresh thread & rests on the tang). Having done literally hundreds of helicoils I've never used loctite. There may be a time when you need to remove the coil & having it glued in place will make it difficult to do ie. a simple job could turn into a nightmare.
When fitting the helicoil make sure that you drill out the hole accurately ie. don't go in at an angle. For small threads in alloy this can be made a lot easier by winding a bolt in & ensuring that the thread is well & truly stripped out (make sure that the metal at the bottom of the hole is strong enough to cope with this abuse!). It's definitely Bubba, highly probably bad engineering practice, but if you've got no easy way of mounting the work perpendicular to a drill then it'll get you out of a fix (instead of letting the bolt bottom out, it's far better to get one that doesn't a place a couple of greased washers under the head so that enough thread is pulled out to give the drill an accurate guide). A better method is to go up in drill sizes, 0.5mm at a time, letting the drill find it's own centre (practice on some scrap metal before attempting your 1st helicoil). Once you've cut the thread in the hole make sure that it's scrupulously clean before fitting the coil (not only do I avoid Loctite, I use a light lubricating oil on the coil). If there's a bit of swarf in the thread then the coil can seize in place which can snowball into a pita. If you try to unwind a coil it spreads outwards, locking the engaged part of it solidly to the sides of the hole. Having said all that, fitting a helicoil really is easy, just get the hole drilled true, cut the thread true, clean it up, wind in the coil (until the end is about 1 turn down below the surface), knock off the tang & you'll wonder what all the fuss is about! Helicoils do make for stronger threads, I've fitted many in engines purely to prevent head bolts, etc pulling out of alloy cases.
You can leave the tang in place if the bolt is sized so that it doesn't reach it, but if a bolt is ever wound in that contacts the tang it'll pull the coil out at the bottom & make a real mess of it all. I once ran a tap down a thread that was clogged with gasket goo, not knowing that there was a helicoil in it. Or that the tang was still attached. The tang caught in the flute of the tap, locking it solidly in place. Of course, I broke the tap trying to get it out & ended up removing the head from the engine & having the tap (& coil) removed by spark erosion. A complete pita, so I always knock those tangs off (a sharp firm tap does it, don't *****-foot around doing it gently as you can pop the lower turn or 2 of thread out. But don't wallop it either!).
What thread form are the stat housing bolts?