I am getting ready to tear into my truck and do a tranny fluid change and am going to put a drain plug in the pan while I'm at it ... what's the best location?

Also, instead of dropping the pan to drain the fluid, since I am puting in the drain plug, I thought I might drill the hole for the plug to drain the fluid ... what do you think?

 

I believe your going to have to get a bung/bolt combo and weld the bung to the pan cause the pan is too thin to cut threads for a plug. It would go in the center of the pan.

 

In the bottom......




Ok had to say it!
I put mine in the bottom towar the rear of the truck,
If you get the nut bolt type, use some silicone with it! Mine leaked no matter how tight I got it! Your best bet it to weld a nut/bung to it!
It will also help drain all of it out. With mine it leaves a 1/2" of fluid in there!

 

you can get a deeper pan for cheap.....

 

You do not need to cut any threads:

B&M DRAIN PLUG-Dodge Cummins and Ford Power Stroke Diesel Truck Accessories - Geno's Garage (which BTW is a really good price - seen them for double that on other sites)

I would say somewhere toward the back of the pan (away from the filter).