Gasket question - exhaust manifold

While assembling installing the drivers side exhaust manifold on the Hemi in my GC, one of the bolts holes had threads strip out.

This happened while torquing the bolts down to the 18ft-lb, and the one that failed was the 6th of 8 bolts.  All bolts had been torqued to 9ft-lbs before this failure occurred. 

I have the helicoil kit and will be repairing the threads, but need to take the manifold back off to do it. 

I bought another set of gaskets yesterday, but the ones already installed are mahle and have a stainless heat shield in the head side of the gasket like the factory gaskets, the ones I bought yesterday are gel pro and don't have the heat shield. 
 

Would you reuse the drivers side gasket, or should I use  a new gasket?

If it has not been heat cycled, it will be fine.

If it has been heat cycled but comes apart intact, it will still be fine.

In reply to Pete. (l33t FS) :

Thanks, that was my suspicion, but wanted confirmation because of home much of a PIA this project have been. 

I've got the front diff out and engine raised to get access to the oil pan gasket and exhaust manifold gaskets, so I'm being cautious so I don't have to do this again. 
 

Gasket looked good when removed, not surprising with no heat cycles or even being fully torqued. 

Hole is drilled, tapped and ready for the insert. My headlamp is dead, so it will wait a day or two before I install the insert and reinstall the manifold. The thread in the other hole for that port are not pretty, so I may put an insert in that one too, while it's accessible, although that one tightened down the first time, so maybe im better off not messing with it.