It made a difference when i sanded down the outer lip of my tb on my gto. it has better throttle response. as long as you stay back away from the throttle flap it will not harm the idle. my gto has been modded like this for nearly 110,000 miles. and no problems.
04 gto 6sp yj, p/tb,tb bypass,160 * thermostat,pacesetter longtubes,tsp torquer 2 cam package, fully custom built 3 1/2 " exhaust, 238/248@50 600/605 lsa 112 n/a, custom tuned by andrea at abel raceing best et on dr's w/slipping clutch 12.70 @ 109, new times to come with the ls7 clutch