M923 speedo adapter for 16R20

[MidnightDuramax]

I have a M923 that I am putting 16R20 XZL on. I am looking for a speedo adapter that will make the speedo read right. I have searched and found many threads but no definitive answers. One answer I found is that you need a HEMTT adapter to make it right. If this is correct where can I get one from?

 

[Beerslayer]

Here's a definitive answer. Do an internet or yellow pages search on "speedometer repair" for your locality. There will be at least one local shop that can make up the adapter for you.

Then measure your speed at 45 MPH indicated with a GPS and take that data with you when you go to the shop. That's all the information they need.

I called Portland Speedometer and they said to just bring the truck down and they would make the adapter right then.

There is also a link somewhere on this site for a replacement speedometer that will indicate up to 70 MPH if you want to do that. It is a Jeep aftermarket parts seller that caters to Jeep restoration enthusiasts that sells them. It is an exact fit for the dash of M series trucks, and just needs the bezel painted. Try searching for it.