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I don't have actual numbers and cannot get them (trans is sitting on a bench at work pending a rebuild) But my 4th and 5th gear RPM's are VERY close. Hardly noticeable at all, ever. My truck has 235ish thousand miles on it, but even 10 years ago with ~150k it was the same way when it was my brothers. If you have larger than stock tires, that puts extra strain on the clutch and may be causing it to slip in 5th gear just enough to negate the OD function of 5th gear. Just a thought.


To make it easy....

Here are the gear ratios:

1st = 3.967
2nd = 2.136
3rd = 1.36
4th = 1
5th = 0.856

And...

3200 RPM = to 60 MPH Fourth gear
3200 RPM = 71 MPH in fifth

Assuming 29" tires. Although tire size wont alter the speedeo to tach ratio unless you change the speedo gear in the tranny.

Basically, 35's will get you the same reading.

Kevin

87 Turbo Intercooled Raider, roller cam, torsen rear diff, LSD front diff, lockup auto with modified converter, V6 brakes, low transfer case gears...