I'm currently running an LLY with a 5spd allison. With my 10,000 lb + trailer it holds a pretty good grade at 70 mph in 5th gear. I'm in the middle of possibly trading for an 07 classic LBZ. I'm wondering what the characteristics of the 6 spd are at 70 mph. Will it be shifting back and forth between 5th and 6th, or does the LBZ make up the difference? If anybody has any experience with both, I'd like to hear your comments. Thanks.

If it does use "Manual Mode" and hold it in 5th. Problem solved.

Exaclty if its hunting lock it out, trans getting too hot lock it out.