Well, ummm.... First, you don't need to drill and tap either PTO plate on the 5600. With an easy-to-find adapter, you can mount the probe in one of the bolt-holes through the plate and casing. The casing holes are through-and-through, and removing the bottom bolts are how you drain the 5600.... Second, mount the probe on one of the bottom three bolt holes on the driver's-side PTO plate. It's tight in there (even tighter on the passenger-side), and a probe sticking over a half-inch into the case may get sheared off unless it's down low.... Third, if you want a probe in the 5600, best thing is to install a set of finned coolers and use the probe mount that's specifically engineered into the coolers themselves. You'll even gain a quart or so of extra fluid, and that's not bad.

I run a cooler on the driver's side with a probe, and the Eaton filter assembly on the passenger side. Overkill, perhaps, but the 5600 runs a bit hot on recommended thin fluid, so what the heck?

 

im guessing u got a set of gauges, boost, egt and trans. if so, i say take and send the trans temp back in, and have them send u a fuel pressure gauge. on a vp truck, fuel pressure is the #1 thing to watch imo.