Stripped out a thread on my intake..... what

[Michael C Henry]

They make a simple Heli-coil tread repair kit (Theree are different names but they are bascically the same)with a couple of average length coils and a tap at the local auto parts store to a full kit with different length coils a special tap, installing tool , tang break off tool ,and remover tool . They never seem to come with the percision drill bit. Once you have the kit, You can buy the coils in bulk in different lengths. The serious kits and souch can be had at a local screw-bolt supply store, hardwhare tool supply etc. A machinist will have the set if you want to just let them do it. I've done this so much, I have the kits in 10x24 through 9/16. The Helicoil tap is special in that it is oversized as compaired to the bolt but the tread spacing is the same. Also the basic heli-coil tap is more like plug tap rather than a starting and finish bottom tap. if you do this enough you may accquire a second tap to make a bottom tap from. Also be sure to use a long enough coil to take the pulling force when used in soft material like alluminum (unless you drill though) in a blind hole. There is no such thing as too much coil. you can shorten the coils that are too long with a cutt off wheel. Make sure you break off the coils tang after installing. make sure that you get that tang as it is Stainless and not verry magnetic and if it gets some where it's not supposed to be as in the case of that tang getting into an FE oil pump and stopping the gears causing evere engine failure.
I pulled two of the Heli-Coils in one head that hold the rocker shaft. Then had to have a machinst install an insert in each of the four rocker shaft holes in both heads . The heads had to be removed as the machinist needed to mount the heads on a machine so to be sure that all four holes in each head are in the same plane so the shaft and stands will slide over them when mounting. The coils wern't enough for this application.