I know the accepted practice is to install the EGT probe in the manifold between the turbo and manifold, heck, even I did it that way on all 3 of my trucks. However after reading more and talking to the Cummins people, if I could do it again, I would put it post turbo for a couple of reasons: First the install is easier as you don't have to worry about FOD'ing out the turbo with metal shavings. Second is in the event your EGT probe were to ever fail, which isn't very likely but still a possibility exists, it wouldn't go through your turbo and FOD out your engine. Finally, there are a set of parameters of EGT temps to avoid for a post turbo install just like there is for a pre turbo installation. Temps that Cummins quotes are usually referenced to post turbo temps. It's just some food for thought...