Speedo eratic over 65 mph

[Brycecarnold1979]

Hey everyone,
I have a 88 gmc g20 rally stx with a 305. The issue i have is the speedo is decent between 0 and 65 but after 65 it just pegs all the way past 85 and bounces around. I am.wondering if this is most likely a gage issue or the cable? I was thinking if it's a cable I would see issues through the speed range? I really appreciate any help you can provide.

[MountainManJoe]

Hi and welcome to the forum.

That sounds like a gauge issue to me.
https://www.howacarworks.com/accessorie ... eedo-works