I have a 1992 Camaro that I purchased new. It is a 5.0 with a T5WC. From the first time I drove it home until about 5 yrs or so ago, I could multiply the Rpms by 4 and that would be my speed( ie. 1000 rpms=40 mph, 1500 rpms=60 mph). For some reason this is not the case anymore and I can't figure it out. Now when I am going 60 mph my rpms are at 2250. I have not changed the stock running gear and I have the same size wheels and tires that the car came with, does anyone have any ideas as to why my rpms are increasing? Thanks.

 

If the clutch isn't slipping the tach is going bad. Actually it is the tach driver board going bad. See the sticky's in the electronics forum here. It shows how to fix it.

RBob.