**Jim -**From my filing cabinet, info from two Eagle sales brochures:

*1979 Model 05*Engine: Detroit 8V71N, C60 injectors, 280 hp at 2100 rpm.

Rear Axle: Rockwell Standard R162, ratio 3.7:1.

Transmission: Spicer 8844A. Ratios First 4.30:1, Second 2.28:1, Third 1.44:1, Fourth 1.00:1.

Wheels/Tires: 12R22.5.

*1984 Model 10*Engine:

8V71N, C60 injectors, 280 hp @ 2100 rpm.

6V92TA, C75 injectors, 270 hp @ 2100 rpm.

Transmission:

W/ the 8V71: Fuller T11905M five-speed, ratios 5:47, 2.67, 1.76, 1.32, 1.00.

W/ the 6V92: Fuller T11905F five-speed, ratios 7:23, 3.92, 2.16, 1.45, 1.00.

Either engine: Allison HT-740.

Rear Axle:

Rockwell Standard R162. Stock ratios for the 8V71 is 3.7 and 3.36 for the 6V92.

Wheels/Tires: 12R22.5 (As a side note, the brochure I have for the Model 01 lists wheel/tires of 11R24.5.)

Where is this 80/60 ratio you're using coming from?

Plugging your tire size into Mallie's calculator (link in your other thread) gives 84.8 mph @ 2500 rpm w/ a stock axle, or 2250 with the 3.36.

So, you've still got some homework to do: find out the rear axle ratio from the tag on the side, and find out what your engine rpm is set at. Then you'll have real numbers to work with, not theory.

FWIW & HTH. . .