I have a 2002 GT, I installed a set of comp cams. (236 int. 240 ex. .500 lift) When I put it back together, I noticed the ticking noise. I never noticed it before the cams but wasn't really listening for one either. It sounds like an injector tick but I just replaced the 30lb for 42lbs. it also has full length headers and off road H pipe, but I used stage 8 locking bolts and checked for exhaust leaks countless times. I also pulled the passenger valve cover (where it sounds like its coming from) to see if a lifter was sticking, I even replaced the stock valve springs with comp. ones when I had it apart for the 10th time. I also replaced the lifters on that whole side. I took it to an engine builder here in Pittsburgh and he thought it also was a lifter, he changed one of the new ones I put in and it still ticks ( but at 100.00 dollars an hour I cannot afford to keep taking it to them). I read some of the forums and seen a few with belt tensioner problems on older models, is this still a problem on the newer 4.6. I don't drive the car often it only has 15,000 miles on it and i bought it with 13,000 2 years ago. If it was a bent valve I thought it would run poorly, but it doesn't. Thanks