I haven't retuned my truck since I did the porting, but it did have a bit of a flat spot off-idle at first, that seemed to go away after a while, like the ECU relearned to compensate for the extra airflow off-idle. I've since installed a Vararam intake and it now has absolutely smooth transition from idle to WOT. The only thing I've noticed recently is that when the outside air temp is hot and water temp is high and I hit the throttle quickly from dead idle, I hear a slight rattle (spark "knock") for a very short period, like it has too much timing for a split second. This might have something to do with the VVT and my tune, I'm thinking, so I probably to tune for that.
I don't think you'll need a retune for it to give you a HP gain, but tuning might enhance the power gain.

 

When i ported mine, i had to take it to get a retune because it was taking it forever to de-idle. Did not know what to do with that extra air-flow. So wheatley told the computer to close the throttle quicker when i am off the throttle, and has worked great ever since. I have noticed that for a while every time i slamed it to the floor it pulled a little harder each time for about the first 5 times i did that, i guess the computer was learning.

 

i seen one of these TB's on an intake the other day at a friends, and noticed that it seems like the throttle blade is centered in the bore, unlike the older LS TB's that were centered towards the bottom for the IAC and PCV passages.


could a man just chuck on the outside of the TB, indicate around the factory machined surface, and take a few cuts to remove the material? or are they offset too?