Shifting at 7000, and stall at 5800, isn't that a 1200 fall back ? It could be your converter maker is not right about your true stall.
My RacePak shows my converter flashes right after the shift to 8500 rpm after a 9700 shift. All the converter people I talk to say the RPM right after the shift is the TRUE stall.
If you shift at 7000, and your fall back is 900, that would mean your true stall is 6100 rpm, Right ?
Just my 2 cents,
Jon