Odometer replacement (with more digits!)

Given the shape my 86 is in, it's highly likely that the odometer has rolled over at least once.  The current odometer has only the 5 'miles' digits (and 1 for 10th of mile.)  What I'd like to do is replace the current one with one with an additional miles digit.  I'm sure I can't do a simple replace of the current odometer, but I thought I'd check with the groups knowledge.  Is it possible? Or is the only real way to add that digit is to replace the entire instrument cluster?

I've been searching through the past emails about the odometer, but so far they've all referred to replacing the existing odometer with an OEM (5 digit miles) part.

Thanks,
Doug

Here is a blurry photo. I will provide details, later, after church.

https://www.ford-trucks.com/forums/1544458-replacing-f150-speedometer-and-tach-with-f600-800-units.html

Thanks - that looks really nice!  Was it a direct replacement, plug-and-play (could use the existing f150 electronic plug to the back of the f600/800 unit)?

The 80-86 pickups all have cable driven speedometers and the speedometer unit comes out with two screws from the back of the cluster. So yes, the medium duty speedometer is a direct bolt in, as long as you get the right year. The very early ones still only had 5 digits plus the 1/10, and at some point they went to an electronic speedometer with a 75mph max.

What I have not seen is a medium duty 6 digit plus 1/10 that also has a trip odometer. If you have a trip odometer now, you would loose that with a medium duty unit.

I believe the wheels can be swapped out, using methods described in the instructions for setting the mileage on a replacement speedometer. The 6 digit plus 1/10 wheels could therefore come from a Canadian Km/Kmh speedometer which are generally easier to find than the medium duty one. I have not done this yet, but intend to try so I can have the additional digit and keep my trip odometer.

The odometer reset instructions are on a tab on this page:
https://www.garysgaragemahal.com/gauges1.html

Thanks, Jonathan!

Doug,

New old stock: [6 available]

https://www.ebay.com/itm/184630002603?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=184630002603&targetid=1263433204214&device=c&mktype=pla&googleloc=9012676&poi=&campaignid=10459841979&mkgroupid=117435520970&rlsatarget=aud-622027676548:pla-1263433204214&abcId=2146002&merchantid=108712546&gclid=Cj0KCQjw18WKBhCUARIsAFiW7Jx6LEBOu7ePAaIFksqE_fLUCsn3JYmelcCj4yH8ZMu7dlR-URtX4X8aApnLEALw_wcB

excellent, thanks!