I have installed a port/polished TB on my 07' Avalanche 5.3L. It is the same size "87mm" as the stock model. Upon starting vehicle, the engline will initially idle a bit high by about 400-500 rpm for a few secs, then settle back to normal range. While in park, if i moderately press gas to about 3000 rpm, it will very slowly return to normal idle instead of falling at a normal faster rate. Shortly after starting, as soon as I put it in gear or reverse then it will take off on its own with "no gas applied at all", not insanely fast but definitely a problem. Finally, when cruising around and letting off throttle completely and using brake, I can still feel truck trying to slightly push through the braking a little. Obviously my brakes are gonna wear very soon until I fix this. This is a replacement TB as the first one did the same thing and I thought that maybe it was a defective TB, but it behaves the same. My 09 Corvette has a TB also from same guy, but it performs flawlessly. Any ideas on how to tune this down? My tune is attached.