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Allison Question

2774 Views 5 Replies 5 Participants Last post by  Diesel Nut
I am planning a transmission swap in my 1998 H1. The donor transmission is going to be an Allison.
I was wondering from anyone who has experience towing how is the 6 speed compared to the 5 speed?

Right now I am having a hard time finding a 6 speed, but I have found some 5 speeds for $900 to $1000. I know if I can find a used 6 speed it would be at least double.

Would that extra overdrive on the 6 speed benifit my truck?
Would the extra money that I would pay be worth it?

My hummer is over 10,000 lbs and has very poor aerodynamics. But I guess anyone towing a large 5th wheel is also heavy with limited aerodynamics.
Thanks for any help,
1 - 1 of 6 Posts
i had an ally 5 speed in an 02 w/ a 8.1 big block
now i have a 6 speed ally in an 06 w/ a lbz
night and day, love the extra gear running on highways and without doing research on it i feel the 6 has a lower first gear ratio, call a dealer and have them look up the ratio's and ranges in gears, it may just be the motor diff but with that in mind i still feel its more than just hp and torq diff. good luck
1 - 1 of 6 Posts
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