08 dodge Durango replaced motor but tranny bolts won't screw in but four turns want could I do? Need help asap

Does the bell housing rest tight up against the back of the motor? If so, and the bolts won't go in but four turns, you have real problems. You also haven't said whether or not you replaced the motor with one of the same size and from the same model year. This has been know to have issues. If the bell housing is NOT tight up against the motor then, if it is an auto transmission you may not have the torque converter seated properly on the input shaft. If it is a manual trans, you may not have the input shaft splines lined up to the clutch disc correctly.