I currently have autometer z-series trans temp, 35 psi boost, and water temp gauges installed. I'm going to order a pyro and install soon as I feel comfortable drilling the manifold. I plan on installing a fuel pressure gauge. Should I get a oil temperature or oil pressure gauge? Would it be worth installing a rear diff temp gauge? I do tow my travel trailer through mountain grades.

 

I would go for the rear diff temp....also a voltmeter gauge (since we know how much our FICMs hate low charged batteries).