I just installed the Grizzly H7589 (the larger unit) on my 1993, 18" Laguna LT184-5.0 resaw. The original fence was a piece of junk that drove me crazy.
The main install problem I encountered was that the sides of the saw's table were rough cast surfaces that had no milled faces that would allow mounting. Also, the sides were tapered and not square to the top surface of the table.
The original fence was mounted to the underside where there were tapped bosses that were milled flat. I wound up taking a length of 3/16" X 1-1/2" aluminum angle and drilled it to match the existing mounting holes. I added some 1/4" thick aluminum spacers to drop the angle down to a level that matched the correct height of the new fence rail. With the vertical leg of the aluminum angle pointing up, it gave me a straight, square surface to mount the Grizzly fence.
I mounted the angle to the table and placed a .025 shim under the cast iron sliding fence to allow for clearance for it to slide. Then I marked the angle aluminum where the fence rail needed to be fastened. I moved the fence to the opposite side of the table and repeated the mark. That allowed me to remove the angle and clamp it to the rail so I could drill through both pieces and then tap the angle out for 3/8" fine thread hex bolts. You can over-size the holes in the rail to provide for some slight adjustment if you need to, but I didn't find it necessary.
The other two problem I had on this particular saw was, the blade removal slot in the table runs forward. So to change the blade you must remove one mounting bolt on the angle that is on the underside of the aluminum angle and loosen the other. This allows the rail to swing clear for blade changes. Since I use the saw exclusively for resawing, that's not an issue for me. (It only adds sixty seconds to a blade change to swing it out of the way and then replace it.)
The other problem I had was the depth of the table on the Laguna. It's 20". Too deep for the supplied Grizzly back railto work. So the far end of the fence will drop off the table when slid fully left. I used the supplied Grizzly back rail and sistered another short length of the aluminum angle on the inside of the far left side. This supports the fence past the table. I removed the adjustable slider foot from the fence and replace it with a small piece of low-friction tape. It now slides like it's on bearings and is supported along it's full travel.
To test it I resawed an 8" wide piece of walnut to 1/16". I did not find that a tracking adjustment was needed at reasonable feed rates. If one is needed however, just loosen the four cap head screws on the fence and you can adjust for drift. I did have to add a layer of painters tape under one set of screws to square the fence to the table. There is no other provision for adjustment provided. Not a big deal, as once it's squared, it done.
The Grizzly fence works great and I could not be happier with it. It allows me to do work that would never have been possible with the factory fence!