hey guys i have a 2007 express with the duramax i wana put a built trans in it so i can run a big tune , where can i get one or the parts?

Start with your local transmission shop. Until then you can start with a bigger pan and cooler to keep temps down.

what trans do these come with?

4L85E trans.

You can add a Transgo kit in the valve body for some improvement, go further with a billet converter, and internal upgrades.

4L85E. How big of a tune do you plan on running ? You need to remember the more fuel you dump the more engine temps rise. Some people with stock vans have the fan kick in when it is 90* out in traffic. Another thing to consider is getting enough air in to match fuel. Stock air box will only flow so much air. If I was you I would start small and take care of the little things first before throwing a big tune at it.

well id like to put a 400rwhp tune in it or maybe even bigger lol its slow , how much $ just a rough figure would i have to spend to run 400horse , also does anyone make a cold air intake?

Slow ?
I am not sure if you will be able to keep it cool with that kinda horse.
No one makes a cold air intake.

What have you done already ?

i mean its slow with the stock tuning, i have a full 5" tb exhaust and a diamond eye down pipe also thought about getting the bd exhaust manifold

vtechthis,

No one has built a trans and tried to run a high tune on the van and documented it yet. I say build the trans for peace of mind and run the highest tune you can, then turn it down if heat issues arise. I don't know where to send you either to get a 4l80 built to hold up to the torque of the diesel. I know Finish Line Transmission can build them to hold 1000hp in gassers no problem, but it seems like I read somewhere that when someone contacted them they didn't think they could get it to hold up to a 500hp diesel? Call around and see what you can find. Unfortunately people will keep skating your answer until someone finally drops the money to try and build one of these things. Goodluck!

I went through this already with my van. In the end the converter would not hold the power and it just flooded the trans with it's internals.
Suncoast makes a converter for them now so that issue should be solved.

^Awesome! What all did you have done to the trans? Did you end up getting the suncoast converter? Thanks

^Awesome! What all did you have done to the trans? Did you end up getting the suncoast converter? Thanks

I had just been beaten by that time and went with a stock replacement and back to factory tuning.
I do have a suncoast converter but it's for my pickup. I will try it again with the van but need to work that out still.