Hi all,

I've done a few 4 and 6 speed auto tunes for gas cars, but this is my first time venturing into an Allison. I've been trying to do some research, but it seems like there isn't a ton of info I've found that talks about firming up shifts or reducing shift times with these Allison transmissions. I'm a bit paranoid after reading a couple posts about reducing shift times and destroying the transmission.

The truck is a 2007 Sierra 2500 classic (older body style) with a Duramax and 6 speed Allison. The stock trans tune is attached below. With a 4L80 or 6L80, or even a 6T40, it's easy enough to shorten shift times and get a crisper shift. Is that okay to do with these? Anything I should be aware of? Any recommendations?

Any help would be awesome! Thank you!

2007 A40 stock.ctz