Revving 4000 rpms on the highway

I used to own a 64 Ford Fairlane that had 3.45 gears in it. 245/60R14 and at 4000 rpms it would sit right on 80 mph.

Like other mentioned a 4.30 gear would probably be taching 4000 rpms at 62 mph.

So you either have more gear than you think, or there is something wrong with the tach/ wiring.

Tom