Don't remove the manifold. That's way too much work for what it's worth.

Someone on this forum had some great advice and I'll pass it along......after you drill and tap (using grease and a magnet), remove the intake tube (very easy) and then make sure the turbo spins. Reinstall the intake tube (don't forget to reconnect the sensor on the intake). Start the truck and let it run for just a couple seconds to blow any few remaining chips down the exhaust. Remove intake tube again to verify the turbo still spins. Put it all back together and you're good to go.

The damage from chips happens when they lodge between the blades and housing causing the impeller to stop spinning then it just sits there and cooks.

 

I have also heard of using a shop vac taped to the manifold by your drill/tap to suck up the shavings as well, never tried it though

 

Someone mentioned about loosening up the Turbo but not taking it off and sliding a piece of cardboard between the manifold and the turbo. That way if any shavings do get down there, it stops it before getting into the turbo. Then just vacuum or whatever to remove them from that cardboard.

 

I unbolted the first exhaust hanger past the turbo and then when I removed the four manifold bolts above the turbo the exhaust dropped a good 1/2 inch. All I did was put a thin piece of cardboard in the gap and taped it in place. After that I drilled and tapped the npt, ran a rag across the cardboard and then reached up into the manifold with my index finger to carefully sweep around for any chips. That was 45,000 miles ago and every thing is ok. To each his own as they say.

 

Did you find any chips when you swept your finger?

I agree that I would feel pretty uncomfortable with the prospect of metal going through the turbine housing.

The official spot for the probe is in the rear half of the collector in the manifold. The turbine inlet is seperated into 2 sections with a thin wall in the middle. If you try to put the hole in the middle, you will be drilling into the wall. You have to put it either forward or rearward of this partition.

I thought the manifolds were one piece on third gens? We change them alot.

If you do decide to remove the manifold, use new gaskets for mounting the manifold and the turbo. Also try to get a new turbo oil drain gasket. Clean the surface of the head too before putting on the new manifold gaskets.