The allison when built is almost tough to beat.

 

This is why i want it. With my 6sp manual and 3.73's with 37" tires im running about 2050 rpms at 70. With a 6sp ally, i could put 4.56 gears in my truck (giving me fantastic low end grunt) and run around 2k rpm's at 80. That is incredibly appealing. Then i would actually have a fast truck.

 

not to hijack this thread or anything but does anyone know if the new 68re will even fit behind the 5.9?

 

It should from what I have read the bellhousing is the same on them.

 

alisons have been running in medium duty's behind cummins and other I 6's for many years now
for instance a 466 international motor can be up to 290 horse
nothing spectacular but they are up in 950 ft lbs of tq
from what i have seen with alisons is what kills them is guys grabbing the shifter and trying to tell it what to do
best thing to do is put it in drive and let it do its job and it wont fail you
come to think of it one of the newer ones i looked didnt even have a shifter
they are push button P R N D and thats it

 

My dad runs an allison tranny behind the CTD 8.3 in his 40' diesel pusher RV. Push button operation.. that thing kicks butt!
Scott