Originally Posted by Wyatt Earp

So, does this Allison have air brakes and a neutral only? Sorry, had to say it.

Originally Posted by DangerousDuramax

Exactly, but when you can afford to build 8 and 7 second trucks you can afford the big boy trannies. Correct again...the greater the rotating mass the harder it is to hold together. The Allison probably isnt going to get a whole lot better than Chris Calkins 9.875sec/139.41mph run "reliably", but for the money that will be spent annually on refreshes it would be more cost effective to go with a Liberty, Bruno, or Lenco. Someone does need/want an Cummins/Allison combo and thats what this thread is for.