1980 Speedo Swap question

[Valentin80Z28]

I have a 1980 Z28 with the 85MPH speedometer. According to what I've read I can't just change the speedometer to a 130 or 150. I'm wondering has anyone ever done a swap from the 85MPH to higher. Because apparently even the fuel guage isn't compatible. Do I have to change the circuit board and all the gauges? Because if so, that begins to get a bit pricey for a "let's see if this works" type of deal. Please help.

 

[Twisted_Metal]

Yes you can swap speedometers.

The speedometer is entirely mechanical in an 80Z.
(81 had a speed sensor for input to the 'puter.)

You can remove the cluster and replace the speedometer with any one from 70-79.
Connect the cable and go.

The 85, 130 and 150 MPH speedometers GM used back in the day were all mechanically calibrated to 1000 cable revs per mile.

I swapped a 130 MPH speedometer(from a 79) into my 80 without having to change speedometer gearing.

However... I did have to change the speedometer gears in the transmission when I swapped rear end gears. That's a separate issue.


Only the 79 speedometer has the 130 MPH top end AND the correct needle to match the rest of them in a 79-81 cluster.

If you have dummy lights instead of gauges... You can swap to a gauge cluster and rearrange some of the wires in the cluster plug to get it done that way too.

 

[Valentin80Z28]

Thanks

Thanks. I appreciate the info. I had no clue why the techs at classic industries told me it wouldn't work. Guessing they just meant that it wasn't original. Thanks again.

 

[sovain]

now I got to go and find a 79 victim... err I mean donor!

 

[joegunn12]

I just did this swap 85mph on my 80z to a 130 from a 79. the 79 needles match the rest of your setup...contact MRFBODY on here he may have one for you, that's where I got mine from,,,,,he's a good guy and will get it out to you pretty quick

 

[joeparamonkey]

Great info like always. just got me a 130 on ebay.