Sm465 Speedo gears or adapter?

[Awann99]

I swapped a sm465 into my truck. The Speedo is slow but about 8 mph. My truck has stock 3:07 gears. Does the sm465 have changeable speedo gears like the th350 that I can swap easily? Or do I need to just get a converter? I found a few threads on the subject but most of the sites mentioned were long gone. Thanks fellas.
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[Accelo]

They certainly do have have changeable gear ratios for the speedometer.
They look like this:

You have to also have a speed at which the vehicle is 8mph slow to figure out what gear count (ratio) to change the to. It makes sense if you think about it this way. 8mph slow at 10mph or 8mph slow at 80mph?

[MJN]

I'd go with the ratio adapter (the little gearbox that mounts to the transmssion) you can either find them used and cross the numbers to the chart within the GM parts catalog or have a custom one made. I had to have a custom adapter for my K20 made to get the speedometer correct- Transmission Center was awesome to work with and they had great customer service. On mine its driven off the NP205 transfer case but same idea with the SM465.
https://transmissioncenter.net/?prod...edometer-gears