Had the transmission rebuilt now when I acelerate with the A/C on it changes to defrost when I let off it goes back to A/C looked for a vacuum line off and can't find anything obvious

This is the "Mode" motor defaulting to its "non-vacuum" powered position when you accelerate. Since you had the transmission rebuilt, it's likely that a vacuum line is connected wrong. Get yourself a vacuum diagram and trace backwards from the mode motor. Also check the mode motor with a hand held vacuum pump to make sure it holds vacuum when it's applied.