When accelerating normally with o/d on when I lift off the throttle rpms fall to 250 300 and cad almost dies...with o/d off I can do the exact same thing and it doesn't do it...I'm thinking time to clean TB and IACV? Any ideas or suggestions?

 

Clean the TB and IACV, also verify the idle speed is set correctly.
The reason it doesn't do it when OD is off, is because the torque converter is holding on.