Engine swap 08 5.7 into 04 ram 2500

[Madmax2023]

Blew the motor on my 04 ram,have a 2008 ram with 5.7 ,want to swap 08 into the 04.
Anyone successfully done this?
Advice is welcome

 

[HemiLonestar]

Is the 08 a 1500?

 

[Madmax2023]

Yes it is

 

[Madmax2023]

The 04 is a 2500 hd

 

[huntergreen]

The 04 is a 2500 hd

Electronics are going to trip you up as the 08 has the mds system. The trans is programmed differently. Not sure if the rear gears are the same or not.

 

[HemiLonestar]

The 04 is a 2500 hd

Yes, you put that in the title.

Yes it is

It will drop right in. You will most likely need to use your 04 sensors due to harness differences. It will have EGR (which your 2500 doesn't use) so you will need to plug that port on the cylinder head and intake manifold or use your original 04 intake (if it's still good, no debris).
Now you have two choices:
1. Leave the solenoids and lifters in place. Default position for MDS is off and without a harness or PCM capable of activating it, it just won't. It'll act like a normal 8 cylinder.
2. You replace the lifters and cam with non-MDS units. This will require disassembling the front of the engine as well as pulling the heads. Will need all kinds of gaskets & head bolts.
Option 1 is the much quicker, easier & cheaper option.

Electronics are going to trip you up as the 08 has the mds system. The trans is programmed differently. Not sure if the rear gears are the same or not.

Which won't matter because the 04 PCM doesn't have the capability to engage it. Regular 3rd gen ½ tons came with 3.55's & 3.92's; normal 3rd gen ¾ tons came with 3.73's (this excludes SRT's & PW's). Regardless, same basic engine.

 

[Madmax2023]

Thanks for the info and options! Was actually considering(for about a minute),swapping the entire wiring harness,something I have done before on older vehicles,but I like your option one…
That will save a lot of time,and I don’t need the cylinder drop off,the truck will be working all the time anyway pulling tandem axle trailer with race Jeep on it. Already started to tear down the 04,once engine is out I will pull the 08 motor and swap everything over

 

[HemiLonestar]

Thanks for the info and options! Was actually considering(for about a minute),swapping the entire wiring harness,something I have done before on older vehicles,but I like your option one…
That will save a lot of time,and I don’t need the cylinder drop off,the truck will be working all the time anyway pulling tandem axle trailer with race Jeep on it. Already started to tear down the 04,once engine is out I will pull the 08 motor and swap everything over

1. You can't swap the entire harness unless you are going to swap ALL of them (the entire truck, plus modules). CAN bus and PCI bus aren't directly compatible. Much older vehicles you can get away with just swapping sh!te around, you can't really do that since the mid/late 90's anymore.
2. You can't use the MDS anyway. 2004 truck PCM isn't capable of it.