Any suggestions on the best approach to upgrading the instrument pannel. my current set up is pittiful. I drive just a straight 2007 GC with the 3.3L engine. I use the vehicle to drive long distances, often in sequential days.

LH Dial = Fuel/odometer
C Dial = Speed
RH Dial = Engine Temp and Gear selection

I'd like to replace them with or simply add:
Tachometer, oil pressure, voltmeter - adding smaller dials for fuel Engine temp.
also considering: water temp/exhaust temp

my preference would be to replace the some of the existing instruments with more relevant groupings of gauges in a single instrument but I've thought of a few complications with replacing the existing gauges. First replacing the fuel gauge would also involve replacing the odometer? then similarly replacing the Engine temp would require the new gauge to have the gear selection? both of these problems arise because some other feature is embedded in the gauge.

I've considered simply adding a 3 gauge cluster elsewhere to avoid the complications with replacing (infront of my oversized fuel or engine temp gauge!) is there anyone familiar with the hookups for each of the gauges
Tach - wired to the alternator???
Oil Pressure - Added component replacing an oil cap???
Voltmeter - straight on single batter but what about a double battery setup with a dedicated battery to powering things when the engine is turned off
Water Temp: I've heard this is installed directly under the top engine cover???
Exhaust temp: no idea???

I'm also wondering if my vehicle came with the hookups equiped for some of the items but were simply not wired since the consol didn't requrie them.

This is my first post on the site. Fingers crossed