The chassis dyno torque curve was quite a bit different from the engine dyno. My best run after a little more tuning was 441 hp @ 5000 rpm and 499 ft/lbs at 3500 rpm with torque coming on much later at ~3000 rpm vs. 2200 rpm on the engine dyno.
Regardless, I have heard that Mustang chassis dynos tend to understate HP/TQ (ie: vs. Dynojet), but have only heard anecdotal accounts of this vs. actual average HP differences. Big numbers are cool to throw out there when someone asks, but my biggest concern is that I'm not optimizing what I have in the car. It seems that the numbers add up enough for me to be comfortable with the tune/powertrain efficiency, so I'll focus on getting the car out on the road and enjoying it!
Here's a link to video of one of the dyno runs for your entertainment:
https://www.youtube.com/watch?v=7GPdxKZFw0w
Thanks guys!
-Todd