new 727 & converter; stumped

New turbo Action tranny and 3000 10" converter. Got the car running on stands, shifted through gears, added fluid until full.
It still has open headers, as we drove it to the next stall. Idle on the Dvorack 440 is 750 to 800, but seems to take a lot of throttle to get it moving (you can roll it with one hand). Owner said it felt like it was chattering.
Any clues?, until we can talk to Forte Monday?