I completed my LT header install this weekend and ran into a few problems. First of all I want to say that I have Kook's headers on other vehicles with no issues but Kook's did a horrible job with the RT's, The headers appear to be very good quality but Kook's did not do a good job with the fitment on the RT model. It's impossible to tighten the back motor mount to the bracket with the bracket installed. I had to install the mount to the bracket and then install the bracket to the block. Once installed the back bolts are riding against the headers on both side and I am afraid that it will rub a hole over time in the headers. Kook's also did not supply a stud that can be used with the dipstick tube so I had to use one of the old exhaust bolts and shim it due to the factory headers being a lot thicker. I also had to slot the dipstick tube mount so the tube would seat all the way down. As far as the green cats go I am also disappointed that they would not fit over my 3" catback system so I am going to have to take it to an exhaust shop and have them to spread the pipes so the will butt up together. I can not install my heat shield around the motor mounts with this design and I am afraid they will be damaged from the heat due to the shield not being there. I don't mind spending money for good products, but the manufactures should make sure they fit!!!!!!!!! Kook's should pay for the modifications and make a heat shield for it since their poor design would not let me put my motor mount shield back on.