Tuned MS3/ETP numbers
Just make sure you remember what you're comparing. He uses a Mustang dynomometer. They are excellent tuning tools, but will always, ALWAYS, read lower than a Dynojet dynomometer. I dyno'd on two different dyno's on two different days, although the days were very similar. Mid 80's, humidity in the mid 40 to 50% range. I found that the SAE Dynojet numbers were only ~5.5% more than the Mustang numbers.
Anyway, by looking at your advertised numbers, I'd like to say your torque converter was probably locked. When mine was dynoed unlocked last year, my torque was like 70 more than my horsepower, and my horsepower was a little on the low side (torque multiplication).
If you went right to a Dynojet as you are right now, in about the same weather conditions, I bet you'd see around 389rwhp/323rwtq (STD numbers), or 381rwhp/317rwtq (SAE corrected) give or take a few.

