Is the stock turbo for the 305hp engines different from the 325hp engines?
The 2003-04 HE341 turbo is very small. Upgrading that to the larger 2004.5-2007 HE351 is an excellent upgrade.
It's a common upgrade that has been done by many since 2004.5! A search on this forum will bring up tons of info.
It will bolt in but there are few mods that you should do.
- Full 4" turbo elbow and exhaust. The 2003-04 trucks have a 3.5" exhaust, the 2004.5-07 trucks have a full 4.0" exhaust.
The HE341 has a 4" outlet but the turbo elbow necks down to 3.5". The HE351 has a full 4" elbow.
- The HE351 has the electric wastegate which the HE341 does not. You will need to convert the HE351 to a mechanical wastegate.
You will need the special wastegate plug for the HE351.
- Some kind of boost fooling. Your Edge likely does this already.
- If you still have the 2003 exhaust manifold, I would recommend to upgrade that at the same time. Even a new Cummins ex manifold is better.
Cummins redesigned the 2003+ ex manifold several times, adding more material every time to deal with cracking and warping.
I recommend to remove/install the ex manifold and turbo as a single assembly.
As Grunt mentioned, you should upgrade your Edge CS. You likely have high EGT's while towing.
Interceptor modules like the Edge are outdated and not that great.
An ECM programmer is much better. Unplug most of your Edge CS and use it as gauges and research ECM programmers.
An MM3 is well worth looking into.
Your sig states your auto trans is already upgraded.
The stock size injectors are totally fine. Even 50HP injectors will cause high EGT's when towing with the HE351 turbo.
I hope this info helps...
HE351 on the left. HE341 on the right.