I swapped my 3.8 for the HO 5.0 and kept the wiring harness from the computer to the engine but not from the computer to the instrument cluster. So when I swapped my old cluster that didn't have a tach and a volt gauge for the cluster that came with the 5.0, the original wiring didn't have the wires for them obviously. I had to rearrange the wires in the existing plugs to make everything else work. So my question is, does anyone know what I could do to get the both to work so I didn't have to get an aftermarket tach. Because my car is the El Cheapo version and it totally looks like a sleeper and I would like to keep it that way as much as I can. I really appreciate any help.