I'm still confused as to why there would need to be a different kit for the Weapon R headers or the MSDS headers.
I have WR headers and I'm using my stock y-pipe. Everything bolts up the same pretty much. All I had to do was buy some bolts with matching nuts, because the stock manifolds are tapped on one spot if I remember right.
So why would this require a different setup... minus the tune obviously. Or is that what your referring to, just getting the setup installed on a car with WR/MSDS headers and having a tune specifically for the headers?
Because if thats the case then your going to have to start factorying in things like what people have for aftermarket exhaust, larger throttle bodies, larger MAF's or any other mod that people might have. In that event I would just have the kit but just not supply a tune for it and leave it to the buyers to take the car in and have it professionally tuned on a dyno and just reduce the price to not include the cost of the tune your providing for the stock applications. I don't know thats just my .02 I guess.