Can of worms
I have 25,000 miles of experience with the juice and the allison....
I do a lot of hard starts.... Lots of long towing around 8,000 to 10,000 pounds..... I like to drive around in level 3 (75HP)... I stay away from the 125 hp setting but have occasionally used it... Never limped.... The inside of my tranny may say different, but I cannot notice a difference in my tranny from new.....
With that being said.... Drag racing this thing day in day out without a transgo kit or more... would be pretty ******* it... Allison or not, its still a transmition and would probably grenade in a relativly short time on the higher settings....
Like most equipment, it will last a long time not being used at its max performance all the time... Drag racing would be putting that tranny to the max all the time... I don't think you could narrow it down to how long it would last...... Cause each one would be different depending on type of fluid, fluid level, and temps the tranny reached...
Im sure you know all this WO, but it was my PC answer, instead of saying "not very long".... But longer than the Torque shift at the same levels...