Got the downpipe installed and put it on the dyno. I don't have back to back, same day numbers but I used same load, same tank of fuel, and same SAE correction factor. The truck is dropping rail psi bad still, lift pump is next test.
Dyno'd 500.xx RWHP right on the money with 40 soot grams (basically ready for a regen ).
So truck mods to date to hit this number; MikeL trans, ATP tuning, S & B dry intake, MBRP downpipe. I'm taking it to the track this weekend to compete in a NHRA event. It is a heavy pig now with the heavy bumpers and winch added to the aftermarket tires. Should be a decent test on real world HP.