I found the

 

I found the transfer case I can't find the Transmision. It's the 3.8

 

Bump ......

 

You need to remove the shifter boot, and the rubber liner boot under that. You will find the vent, on the side of the shifter bolt down plate on the top of the trans. It has a plastic vent cap on it, and if you pry too hard, you will break it, just be careful.

If you are going to run the vent up higher, you may also want to consider replacing the clutch disc, as they are prone to detonation if it is submerged in water, and you engage/disengage the clutch with the engine running.
I am looking into an aftermarket one myself...

 

Centerforce make one that fits there's a thread about it.

 

That is the one I've been looking at.

 

If you don't shift in the water you'll be alright. I'm going to wait ether until it goes or I throw a diesel under the hood.