I will reply in bold. It's not easy to put exactly what I want to say into words in writing. It's just not my best attribute I guess you can say?
Jer my man, your totally misleading people. From what your sayin, you should just stick with separate duals on out trucks without a crossover.
The cross over isn't going to help unless installed in proper location. On the passenger side is not even close.
Unless you tune for the new system, the stock ECU can only adapt so much. Free flowing exhaust is best, but to "use it all", it must be tuned for it.
There will be lean spots that will need to be adressed.
I can assure you that a X-Pipe or H-Pipe will increase the low end even with a longer pipe coming from the driver collector. Its simple flow dynamics.
You are forgetting about the exhaust pulse timing. If the pulses "hit" at the same time, no scavenging will occour. The object is for each pulse to help pull, not meet and "bang" into each other. We are dealing with pulses here and not steady flow. If eqaul length meant nothing, explain equal length headers and how they are better than non-eqaul length.... all the rest being equal. (pipe ID, port size, etc)
We all agree that the efficiency is less when the distance is different from one collector then the other in a X-Pipe or H-Pipe application. But to say that it will only change the sound and create no performance gain, um no way possible.
If you can figure out pulse time and adjust for it with pipe length, then you "can work around it". Sort of like mounting tweeters a phase length away from the mid/woofers (I may have said that wrong....)
In short- Equal length from exhaust port up to the X or H -pipe = more power than non-equidistant.