I recently installed a set of Grot headers on my 95z. My butt-o-meter was telling me that the car was faster than it was before. I was first able to take it to the track this friday and the car ran almost .4 tenths slower than it did the week before the header install. The only thing I could think of that could cause this kind of problem is that the computer is picking up false knock. The plugs are new, the wires are new, nothing is burnt or arching. I have not yet got a chance to hook it up to my scanner to see how much timing is being pulled. So the real quesiton is, if this is the problem, will an LT4 knock module fix the issue? Can I just pick one up at a GM parts counter? Does anyone know the part no, I tried a search and came up empty. I would order it online, but I dont feel like waiting for it

. Also, I had the computer tuned for the "knock desensitizing" feature, along with the headers. Would this rule out the knock retard? The headers arnt leaking at all as far as I can tell, and even if they were, would that cause almost a half second of lost time?