I have swapped out all my gauges, not with auto meter, not sure if Autometer has a 0-30GM fuel gauge or a 24V voltmeter, of course you will probably have to change to matching sending units for oil pressure and water temp, and run them on 12V unless they offer 24V gauges which would not surprise me.
You will also need to mod the mounting brackets as the HMMWV dash is around 1/2" thick or maybe a little thicker.
I went with imported stepper motor gauges and love tham as most of what I have used is programmable for the type of sensor.