[Maury Novak]

Ren Man,
Attached is a chart that shows what RPM to expect at 60 mph in fourth gear (1:1) based on rear-end and tire size. This assumes your tach is correct.

If you don't come close to these reading you need to adjust your speedo. If you have an electric speedo, then adjust per the speedo instructions.

If you have a mechanical speedo, cable from transmission to speedometer, then you will need to change the speedometer gear in your tranny.

If you speedometer reads high, then go with more teeth to slow it down.

If your speedometer reads low, then go with less teeth to speed it up.

Hope this helps.

Maury