One thing I thought I'd toss in for anyone installing one of these... I've seen them installed in a couple different positions. (and done it both ways myself)
You can set the screen a little lower, and not have to cut into the lens of the tach, but you do have to cut into the board and the corner of the cluster more, and the corner of the screen runs under the bezel.
Cutting into the tach lens and raising the screen up looks much more symmetrical, but the tradeoff is that the illumination of the tach scale is cut in half... It looks a little goofy at night with only the upper half of the numbers illuminated. If I were going to do another, I might consider taping or painting over the area completely so it's not illuminated at all...

