I believe that the low dyno number (437 hp or therabouts) was due to two things.
Many, many trucks there dynoed a lot lower than they should have. Rhall has a 600+ hp truck, and he only dynoed 10 hp more than I did. There were others with aftermarket turbos, custom tunes and built trannies that were in the 400s. Something was not right, but I do not know what.
I also think that my truck was definitely starving for air. This new intake has made a marked difference in smoke reduction, and I have seen about a 2 mpg increase in fuel economy. More air is helping my engine to run a lot more efficiently.