My battery drains over a 2 to 3 day period. I have used the measuring of the voltage drop across the fuses to no avail. So now have an ammeter in line with the battery and awaiting everything to go to sleep. After that will start pulling fuses...starting with what should not be awake. However it occurred to me I have no idea what the correct current should be? Right now its sitting at 140 mAmps

 

You are on the right track. While the current is going through the meter you can now pop the fuses out one by one and see when it goes down. Mine also drains in 2-3 days, I suspect its my radio - will have to do that very same procedure soon.
I suppose another method would be to leave the battery connected as is and then pop the fuses out one by one and use the meter in current sensing mode to bridge the fuse gap.

 

140 milliamps is a little high. I can vouch on my 2004 Frontier that it can just sit for 3 months and start right up. It has its ECU of course, plus an aftermarket CD player with station memory and a clock.

Battery drain in 2-3 days is ridiculously fast, something is wrong.

I'd start by pulling the fuse for the stereo, and second pull fuse for the alternator, and see if the drain drops.

On my 1998 Frontier 15 years ago, had bad electrical part of the ignition switch, and observed it going into electric motor stuff operating under the dash - with the key out !!! So replaced that right after that. Apparently that phantom stuff would go on sometimes and immediately drain its battery.

 

Need to give it at least 30 min. after shutdown and opening door for everything to go to sleep.
CD stuck in the player was a common battery drain in early trucks.