So is this information with the usual 75mm throttlebody upgrade?
Also if you notice the Gen 3 flow charts stop at 12k RPM, which is at the low end of when people would swap out for a GEN V. if you follow the charts you will see that the 8hp minimum gain on a 3.4/3.6 setup would become even more pronounced at 12.5-13k the GEN V looks to be around 42-44 hp on the chart, while the GEN III would be in the 55-57 hp range,
Also you forget the age of the units themselves, as nobody rebuilds these things usually so you figure the vehicles with GEN III's are old enough to legally drive themselves. I'm sure alot of rotor coating on the early blowers, along with age related play would lower the VE alot from those perfectly new specs.
Just saying I'm swapping mine due to age related failure and for $300 for a GEN V and N* that will net me at LEAST 8 proven HP and probably much more I think it is worth it.