Tach in a 78-83 Regal/Century Dash-How To


What's Fuel Injection?
Hey B4B people, long time no visit in this forum. :) Been busy with my LS 2+2 and LC2 swap on my century wagon. My drawthrough cutlass has been sitting in storage for 2 years.

Did a quick tachometer install on my century wagon and thought I'd put a how to up for a factory appearing dash. Its being hooked to a LC2 4.1 engine but it should apply to any 78-83 dash.

My 80 century wagon had no dash clock so only a speedometer and fuel level gage.

I found a 78 turbo regal that was being parted out and bought the dash cluster. A 78-80 also has no VSS and my 87 LC2 harness needs a VSS input so I bought a 3rd dash cluster for the VSS speedometer. I put the 81+ speedometer in the 78 cluster and had to grind a small notch in the plastic housing to clear the fiber optic sensor.

Anyways, I started by gutting the clock housing on the spare cluster and leaving only the bezel and face, i bought a bosch $32 tach from advance. The tach has a selector for 4 6 or 8 cylinder.

Took the bosch tach out of the housing, ground the needle off and removed the dial

It's not perfect alignment but its pretty close, 250rpm max off. I also drilled the two mounting holes in the clock housing

The clock has 3 needles, 2 black and 1 orange, the 1 orange one is for the seconds and didnt match the black needles so I cut one of the speedometers apart and robbed the needle, i had to drill the center out

Mounted the tach and pressed the needle on


It doesn't have an RPM label and doesn't look like a tach fully but it was an easy 1hour project that didnt require any printing or decal design. Just have to know 12 is 0RPM 1 is 1000 ect.

For $32 and under an hour of time I am happy!


Well-Known Member
Excellent. Thanks for writing this up!

I did something like this with a factory tach from a Cutlass. It also had a v6/v8 switch. I mounted it in a clock delete plate. Biggest issue was the delete plates don't have a light bulb for night time. Plus it didn't have any numbers. Using a gutted clock is a much better idea.