Quote Originally Posted by NoTaTurBo View Post
He has the 4 speed. That is all that came in the 08 silverados. 6 speeds weren't introduced until 2009 and they were only in a crew cab. Go with Nelson Performance. I have his tune as well as many others and I am very happy with it. I owned a ton of handhelds before while I was in high school and my custom tune is way better. It is smoother as well as quicker. All he does is sends you a pcm. It takes about 10 mins to swap them out. It is very easy and he will send you directions with the pcm on how to do it. Then you are tuned! All you have to do is send yours back and you are good to go with free retunes for life!
The 6 speed transmissions were actually used in the 2007 New Body style HD trucks as well. There are many customers that we have tuned both 2007 and 2008 that have the 6 speed transmission.