Comparison of the normal uncut version (TV) and the Director's cut.
Both version are contained in the US DVD of Fangoria/MTI Home video. The different parts can be either automatically switched during the movie or they can be obtained in the deleted scene section.
According to a directors quote the actual ending was inappropriate back in time because it was far to blackend and disturbing. Today it can be considered harmless. After all, this movie is a cult flick of the 70s which should be discovered by every horror fanatic.

A new German DVD by CMV contains the uncut version but the missing sequences can be seen in the deleted scenes section as well.

Uncut theatrical version = 83:28 min.
New director's cut =88:18 min.

25:39
The scene where Peter and his drugged gandfather enter the house differs. The runtime of the theatrical version (TV) is 15 sec.. The extended DC offers 102 sec. After Banner takes a seat at the table he looks around and starts to halluzinate because of the LSD he had consumed. He says that Peter's parents are going to return and take him with them. Banner angryly demands they should disappear. He stands up and opens the door. After the parents disappeared, as he actually thinks, he goes back to the table. Peter, who feels a bit disoriented, thinks his gandfather is simply drunken.

50:04 The conversation between Andy and Sylvia is longer in the DC. The TV has a runtime of 29 sec. whole the DC has exactly 90 sec. After Andy told his girlfriend that he say Shelly dying he is completely exhausted.
He thinks that other members of the sect are now after him. Sylvia tends to stay in the stable for the night. Andy gets up and goes forward to the grid (also available in the TV, but shorter). Sylvia tells him she has to go now because the others would be in sorrow about her long disappearance and she also says she will talk to him by tomorrow. Both say goodbye and kiss each other. When Sylvia leaves the stable Andy yells that he loves her.

82:20 The ending has a runtime of only 26,5 sec. and ends with the conversation of Dr. Oaks and Roger. The ending in the DC is far more disturbing and has a runtime of 168,5 sec.
While Dr. Oaks leads Sylvia and Peter to an ambulance car the DC shows intercuts of a window. Inside there is Mildred. She is looking out of the window. After Oaks and Roger had their conversation Roger enters his apartment. Mildred is now lying on the bed and Roger tells her that the nightmare has come to an end.He takes a seat on the bed and insures Mildred she does not have to worry anymore and puts away his gun. Mildred starts to kiss him passionately. Suddenly there are noises of suspense and one can see how she takes the gun and aims for Roger. He looks extremely astonished and she pulls the trigger without any emotion. Roger is pushed back and spills out blood. Mildred looks happy. She is also infected with rabbies.
Scene change: Peter is sitting in the porch of a house. Two sherrifs appear and Pete tells them he is guilty. He wants to be responsible for what has happend because he feels guilty. He shows his hands to receive the cuffs. One of the sherrifs laughs and arrests him. Because of his thin arms Peter can release himself quickly. The sherrifs make fun of him. Pete is angry and tells them to go into the house to see what happend. The sherrifs get back into their car and disappear. The DC ends and the outro fades in.