Thought I'd write up a DIY on the tachometer swap similar to what Kev wrote up in his build thread but with a little more detail for those of you who want to do this mod.
Start with removing the instrument cluster from the vehicle, pretty simple, 4 screws to remove the bezel then 4 to remove the cluster.
Once you have the cluster removed start with the face plate, there are about 9 phillips screws located on the back around the edges which need to be removed first.
Remove the face plate and it will look like this.
Now remove the original tachometer from the cluster assembly, there are 4 phillips screws in the back along with a single 6mm nut holding the harness.
Then remove the black plastic (bulb guide?) thing beneath the original tach. It has two phillips screws from the back of the assembly. Unfortunately you will loose the "Brake" and "Beam" warnings which are integrated with the OEM tach. I simply removed the bulbs from the cluster assembly.
Now set the cluster assembly aside and remove the clear gauge lens from the face plate, it's held by 6 small phillips screws at the edges.
And now for the part that isn't reversible if you choose to return your car to stock. Although if the cut is made correctly, you wont be able to tell if you had to put it back to stock. I drew a line using sharpie leaving one inner blot hole on each side of lens.
Install the right half of lens.
I purchased an Auto Meter 2300 Auto Gage, Black 3 3/4" 8000 RPM Tach. From the gauges I've seen this one matched the best with the Hako cluster.
Remember to remove the backing of the Auto Meter gauge and flip the jumpers on the circuit board #1 on, #2 off. This is for use with 6 cyl applications.
I used a washer and long screw I dug up in the garage to mount the Auto Meter gauge using the existing hole in the back of the new tach. Feed the wires through and mount the unit through the back of the cluster assembly.
Re-install the cluster face plate. (Note: I had to leave the mounting screw for the new gauge a little loose to install the face plate and position the gauge correctly once installed. If everything went as described your finished project should look like this,