Speedometer needle sticking

The car has set for years and I am slowly rebuilding it. The other day I installed the cable and everything was great. Drove probably 75 miles. Next day nothing. I thought did the cable break but then noticed mileage is still rotating. After coming to stop this time it takes off and we gey to 55 and stops. Now sitting in my garage still says 55. Is this just a clean job? Anyone else have this issue?

88 st165

5s block
3s gen 3 head
2000cc injectors
Precision 6062

Just seems to be another flaw n this build....

Nothing to do with your build man.
If the odometer is still working ok it's in the gearing for the speedometer.
It's a somewhat difficult job to take the speedo apart because it's not designed to come apart.
But it can be done.

Oh I know its not my build its cable driven. I was just curious if others had same issue.

Figured I'd give some details of my build. Everyone likes to see and hear of something being done besides stock.

So is acrewed together or rivets? Sounds like you have experience in tearing one apart.