At that weight your hopes should of been met IMO Sounds like a very good setup, did you happen to see what the rpms were doing or have a playback and know what flash stall and fall back rpm was.
Hopefully its something simple because it sounds like good stuff. I used to have a 383sbc that wasnt as good as your stuff listed, ran 6.0's @ 2700lbs so I'd think yours should run that for sure.