Ive always read and done a drill and tap WHILE running just to be safe. Here is a direct quote from the Quadzilla Adrenaline manual...

EGT Probe Installation:
1. Using a sharp 21/64 drill bit with your engine running, drill
a hole slowly and carefully in the exhaust manifold between
cylinders 3 & 4. * See (A-14) for reference. * Tip: Greasing the
flutes on the drill bit will act as an extra precautionary measure
to help catch metal shavings while drilling.
2. Use a 1/8-27 NPT tap in the drilled hole. The engine should
be running during this process as well. Make sure that when
you start your tap it is parallel in all planes with your hole. Not
getting the hole tapped straight could result in an exhaust leak.

 

ah ok, i will try that thank you for the info

 

Actually your probe isn't in the preferred spot. It should be on the left, reading 5 & 6 cylinder temps. They tend to run the hottest being in the rear of the engine. I guess the Quad instructions aren't correct.
I've drilled lots of manifolds without the engine running, just grease the drill bit and tap. Never a problem.