Manual transmission fluid, to overfill or not to overfill?

I'm about to change the transmission fluid in my 2009 Tacoma 6 speed manual. I've been told by some to slightly overfill the transmission by jacking up one side of the truck. I was told that the transmissions were overfilled from the factory, and that it will be less clunky with 1/8 - 1/4 of a quart more added. This doesn't sound like a great idea to me, but I've also never done this either. So, should I overfill the transmission? If I'm not supposed to overfill it, then do you just pump enough fluid in until it starts running out of the fill plug? I don't suppose it's possible to measure and get exactly 1.9 quarts from a bottle into the horizontal fill plug. Thanks for your advice.

Austin

 

Over filling is called over filling for a reason. I wouldn't.

 

I wouldn't. Fill until it comes out the fill-plug.

 

Thanks guys!

 

Not an exact science, On level ground fill until it weeps out of the fill hole and let it go.