Hold on people - I don't recommend bothering.
I'll see if I can find it (don't have the link anymore) - this "uncut" version of the Lynch Dune film isn't. It is an unauthorized rehash that adds little genuinely new footage, while beefing up the running time by re-using stock footage. Wait - aha!
The big confusion on Dune came from the expanded syndication television recut that circulated starting in the late 1980's. Sans commercial breaks it's at least 45 minutes longer than the feature version. Since it aired over two nights in two-hour chunks, it's often called the four-hour cut, but that time frame is padded with commercials and a lengthy re-cap at the beginning of the second half. In this expanded version are many scenes we'd never laid eyes on, and others extended and fleshed out with new footage. New insights are given to every aspect of the story. Paul's introduction to the world of the Fremen is particularly improved. The process of milking the 'water of life' from a baby sandworm was shown in complete and convincing detail. Musician-warrior Gurney Halleck (Patrick Stewart) actually plays the stringed instrument he is shown carrying at the beginning. For those fascinated by how versions change the perceptions of movies, this long cut was a real treat.
The only itty-bitty problem with this long TV version is that it wasn't David Lynch's. Universal either lost or never got Lynch's approval and participation because Lynch had his name removed; the usual 'Alan Smithee' director's credit was put on the TV cut. Lynch's writer credit was replaced as well with 'Judas Booth.' In its conflation of the names of two famous betrayer / villains, the alias might have been suggested by Lynch himself as a bitter joke (or the studio, indicating a Lynch betrayal?).
Editorially, the new version is an artless pastiche that tries to dumb-down Dune and smooth over some of Lynch's nastier moments. TV censorship excises the disturbing Harkonnen heart-plugs, and the Baron's spitting on Francesca Annis. The starfield opening with Princess Irulan (Virginia Madsen) is replaced with a new six-minute prologue. A new narrator intones a rambling, repetitive, mind-numbing speech about the various planets and their feuding clans, all backgrounded by cheesy character sketches of the costumed leading players. Flat and dull, this exposition seems even more redundant when Paul's computer-viewer gives him a similar expository rundown in the very first scene.
At first glance, there seem to be many more shots of spaceships and battle action in the TV version of Dune. The majority of these are actually repeats used two, three, even four times. Because the TV version is a pan 'n scan, shots could be repeated by showing first the left extreme of a shot, and then using the right extreme in a subsequent cut. Combine that with optical blow-ups to multiply the shots of arriving Harkonnen spaceships, and a lot of this material is just blatant padding, that could not be duplicated in a letterboxed version without revealing its cheating nature. Even more curiously, one new truck-in on the Emperor's pyramidal battle tower reveals it to be just a black and white line drawing!
Whether or not the unhappiness over Dune started it all, the fact is that David Lynch is adverse to home video and seems to be the one blocking new releases of his films on laser and now DVD. Although that is the 'unofficial' reason quoted in other articles, it is reinforced by the constant announcement and subsequent cancelling of video reissues of his movies. Perhaps he is a purist who beieves his films should only be seen on the theater screen, and has allowed the initial video releases only because they are a distribution necessity. Or maybe he is the kind of artist who refuses to let his previous work be fed through the commercial money mill. Twin Peaks: Fire Walk With Me seems to have come the closest to being a project Lynch might have pursued for video; but only closer sources would know for sure.
Real bummer, Dune is sweet