Here is what i suggest for EGT. You want Pre-turbo for sure. I have used 2 of these gauges on 2 different 7.3L trucks.

ISSPRO Gauges at DieselManor
R3607TR-CT Pyrometer Kit*
ISSPRO R3607TR Pyrometer with 6' Hi-temp Lead Wire and R650A-HT Hi-temp (2000°F) Inconel tip adjustable length Thermocouple, Band Clamp style.
Price $143.95
This Pyrometer is recommended for Pre-turbo install.