I see a lot of guy that have the 07 NBS 4.8 has 3.23 gears from the factory. I have the one with 3.73 gears and also has the tow/haul mode button on the shifter. Does that mean i also have 4l80 transmission or do i still have 4l60 transmission. When i looked it up in the manual it said either has the Allison or 6 speed transmission but i know i don't have the 6 speed one in the truck. Call the dealer they was no help.

 

you have a 2007 4.8/60e 4speed combo. the 2009+ 5.3/6.2 combo came with the 6speed

 

I had my truck tuned so when activated it run even better. So just thought i might had another trans since i got the higher gears from the factory.

 

nope, just a 60e. im shocked to see you have 3:73s considering they sell the 4.8 to be a gas saver almost....3:23/3:42s

 

My 07 Silvy with a 4.8 came with 3.73 and that was off the lot not ordered.

 

hmmm....yall are lucky i wish my pos came stock with 3:73s i would have never changed gears.

 

I'm glad to I was going to change but going just make it pos and call it a day on that. I was just hoping the trans was different so I didn't have to change when I put the turbo on it

 

it's ok....if i was you, id go with a Performabuilt LVL 2 unless you want to go 80e

 

Don't want to sound crazy but what's LVL2 so I will know what to research

 

It's just the model of the tans they sell. It's still a 4L60E, they just make improvements and sell it as a Level 2 type of package.

Search Perfomabuilt and it'll give you the breakdown of what each level includes.