2003-2006 motor parts interchangeability
 

Hello, I long story short I have a 2003 235 CA motor with a bottom end knock. I I also have a 2006 325 motor that has smoked cylinder walls. I am going to tear down the 03 and am wondering what if any parts are interchangeable? Is it worth changing out the head,cam,turbo,crank? what gives the 06 more power than the 03? I am just hoping to build one out of two and want to use the best of what I have.
Thanks,

Pistons and injectors are the main parts that don't interchange. If the cylinders are good on the 03 then yes you can make a good motor just be aware that the 06 pistons are wasted too. Which motor do you need?
Cheapest fix pull the crank from the 06 and put in the 03 WITH THE BEARINGS! If they look good! hopefully the knocking cylinder piston rod is still good not beat up if it is then the head has to come off and the rod replaced. Your better off getting a reman for 3400. to do it right!

I need the 03. I planned on ring and bearing the motor. Its all coming appart. Is there any benefit putting the 05 head on the motor? I am a decent engine builder just unfamiliar with this motor. Doing my home work.

03 04 had an issue with dropping valve seats so yeah use the 05 head

I pulled the motor and the #6 rod bearing is smoked. Rod looks like a rainbow. Do you know if the 06/03 rods are interchangeable?
Are the turbos the same worth swapping? Thanks for the heads up on the valve dropping issue!
Thank you for your help,much appreciated!!

Rods are the same!06 turbo is better

Injectors are interchangeable between years. But there is a different spray pattern. Pistons are a different design. Some guys say the 03-04 pistons are more disable. Connecting rods are the same between the years. However some early 03 share the same rods as the 98-02 VP44 trucks.

The rods appear to be the same. The 03 has a machined surface on the side of the rod and the 06 doesn't. Thats the only difference i can see. Will there be a noticeable difference between the vp44 rods and the others? I was looking in the block and it looks like the 06 has oilers that are bolted in,that spray the bottoms of the pistons,The 03 doesn't but has the bolts and what appears to be a oil passage to install them. Can I swap those over as well or do the interfere with the Pistons? I haven't had a chance to check the fitment yet. Looking at the cams they appear to be the same they have the same numbers cast into them other than the date code am I correct in this assumption? Once again thanks for all the info.

One last I hope question. Is there an indicator on the head gaskets?
Looks like there are a few different thicknesses!

Only have to worry about that if you deck the head or add a cam. You can use any one you want. Not that much difference to care about!