If we look to the 2000 model year GT's and compare the diference between the 2 engines, maybe we can pin-point where the noise is coming from. I have not heard of any 2000 GT's making this noise, so it must be the diferences from model year 2000 engines and the 2001, 2002 engines. 2001's have higher compression ratio, diff. water pump. Cant be the intake because GT's have a diff. intake than the Bullitts. You guys can see where I'm going with this.......anything else anybody can add?