2004.5 to 2003 engine swap

[erikz]

I see there are many discussions about the inability to swap injectors between 2003 and 2004.5 engines. However, could you install the entire engine from a 2003 (305hp) into a 2004.5 (325hp) truck? Or would this be a disaster? I have a 2004.5 which is still running fine now but I also have a 2003 parts truck, which was running well, and if my engine lets go could I successfully swap these? It might sound like a stupid question (please go easy on me if it is) but thought I would throw it out there anyway for when the day comes.

 

[Darkbloodmon]

There are no stupid questions here. But you will need thick skin. Interesting question though. I don't have any experience with engine swaps, nor do I hope to with a Cummins. But I'll be following along for details on it.

If you're explicitly talking about the engine alone, there are a few things you'd have to do some research on. The 305 is a 6MT.

The adapter plate may be different from an auto truck. Will the drivetrain line up as it should if you're putting a 305 engine in an auto truck with or without a transfer case?

I don't know if the 04.5+ cluster or harness will interface with an early 03 04 engine or vice versa. I know for a fact that the early 03 04 clusters are not interchangeable with later model trucks. You will blow fuses and potentially damage the cluster as it is a computer in itself.

It'd be a safe bet to move the ECM with the 03 over, but (harness hooking up the same for all sensors?) I'm not sure what an 04.5+ ECM would do on an 03 04 engine. The 04.5+ ECMs have additional pilot injection programmed in as an emissions transition measure. 03 04s didn't.

The engine alone should drop into the frame no problem. But more details on the 04.5+ frame and drive train would help, Auto? Transfer case? Long Bed? Swapping the manual over or leaving it? etc.

 

[AH64ID]

Unless you do a wiring harness swap I would not put a 04.5 into a 03. Everything would bolt up and work with minor mods, but the 03 ECM shouldn’t be used for the 04.5 injector-piston design without full custom tuning even then the 04.5 is a weaker piston design.

An 03 will work fine in an 04.5 thou, as that style piston works on both programs thou any swap between generations of 5.9 HPCR’s should get custom tuning.

I ran 03 style pistons and injectors in my 05, way better than the 04.5-07 piston style.

 

[erikz]

Hello, I would be putting the 03 engine into an 04.5 truck. I would use all the existing 04.5 wiring and ECM etc. Basically the 03 engine would think it's an 04.5 in a 04.5 truck. It's in an automatic quad cab short box 4x4 all stock. I would also swap the turbo from the 04.5 onto the 03 engine. Thanks.

 

[AH64ID]

That will work fine on stock programming, but you would still benefit from full custom tuning.

 

[erikz]

What would the advantage be on a custom tune? Is the 03 a better engine or respond better to tuning? Could I just run a programmer? If I leave the programming stock on the 04.5 ECM would the engine still give me 325hp? Thanks.

 

[AH64ID]

What would the advantage be on a custom tune? Is the 03 a better engine or respond better to tuning? Could I just run a programmer? If I leave the programming stock on the 04.5 ECM would the engine still give me 325hp? Thanks.

The custom tune will take the differences in piston bowl and injector spay angle into account on injection timing.

Box programmers or even "custom" tunes that aren't built specifficaly for your vehcile will not take those into account.

Having tuned several 04.5-07 motors with 03-04 injectors/pistons I can tell you there are definitely differences in programming. The 04.5 ECM will still work with the 03 setup but it's not optimal and may or may not make the same power as with a 325 ECM.

 

[erikz]

OK that's good to know. Would i have to send my ECM out for that to get the custom tune? I live in Northern Ontario and don't know too many people in this neck of the woods that could handle that. I appreciate your help. Thanks.

 

[AH64ID]

You can do it via email with tuner such as the MM3.

 

[erikz]

Awesome! Thanks.