Twin EGT readings?
 

I recently purchased a replacement thermpocouple for my truck and after many tries of removing the old one I think its best to not force it. Could I drill another hole in the manifold towards the back side of cylinders 5 and 6 to get a better reading? I've heard 5 and 6 run hotter than the rest and the current thermocouple is place to the front of the manifold / turbo inlet. If I did tap the rear of the manifold, could I run both egt's together to the gauge? And would the gauge just read the hotter of the 2?

First... one t-couple to one gauge; do not wire together.

Yes, it is ok to tap between 5-6, but it won't be your hottest reading. (BTW, you are reading only 6 there, not 5) That will occur at the collector. FWIW, I have three probes installed on mine, two at the collector (one for front 3cyls, one for rear 3 cyls) and the last one in the runner at 5 where it would show the average of 5 and 6. That last one is consistently 100-150* below the other two at the collector.

My current probe is at the collector but towards the front of the divider.. Am I getting a accurate reading of 5 and 6 there?

Um.....no. The rear of the collector is the warmer side. Do you want two probes/two gauges? If so drill and tap the other side of the collecter as well.

I run two and think it is a good idea...

If you just want to remove it...spray some thread penatrant...let it sit for a while...then remove it. If the adapter is what is stuck...don't worry about breaking it...you can drill it out with a slightley smaller bit...then use a tap push the remaining crud out...then chase with a 1/4 or 1/8 npt tap.

Clear as mud?

Tried every penetrating oil that I could find, that baby aint coming out. Even tried the wax method.. I think I'm just going to leave it and drill another hole on the back of the colletctor to get a better reading from #5 and #6. Maybe someday I'll get another gauge to monitor both but with my mods I'm thinking I dont need it? I was concerned with drilling another hole and possibly weakining the manifold.