Trucking: rear end gears, rear end gears, bob stephens

Question
I have a international 4300 truck with a DT466, 266hp engine and allison 3000 trans.& 411 gears. The engine runs at 2300rpm at 65mph. The truck weight is about 20000lbs. It is used for service/mobile truck/trailer repair. Is this a good rear end gear? Off the line is good but im I too hight for the highway?
Thanks Dave

Answer
Hi Dave.

I've driven many 4300s and they all were good off the line, and sounded like they were ready to explode at highway speeds!  Your 4.11s are about right.  New 4300s go as low as 3.54 to as high as 6.17 (from what I've seen). With your transmission, 4.33 and 4.63 are very common too.  You should be ok with what you have.

Hope this helps!

Bob Stephens