4.7 to 5.7 swap

[C L Martin]

Been building gen 3 hemis for 15+ years & finally built one for myself. I have a 06 1500 2wd slt with a 4.7. I have a 04 2500 5.7 4wd donor truck. I plan on using the engine harness, throttle cable & throttle controller, motor mounts, accessories & torque converter from the donor. Several questions. Will I also have to use the harness that goes to the dash, fusebox & trans? Will either ecm work after reprogramming? Are there any pin out changes from 04 to 06. The donor truck is a late 04 with the same ecm plugs as the 06. Thanks for any info

 

[HemiLonestar]

I am curious as to what throttle cable you will using from the donor, as ALL 3G-4G hemis are fly-by-wire.....
Mixing those two years isn't gonna work out well for you. 2004 is pre-CAN PCI bus and your 06 is CAN bus. The electronics aren't directly compatible. 06-08 hemi electronics would be directly compatible. Best way to go about it would be to get 06 1500 5.7 PCM and send your 04 harness out to get modified correctly. Without knowing emissions laws where you live, another wrinkle you may run into is EGR. All 04-08 5.7 1500's use it; the 03's and 04-08 2500/3500's did not. Also 2006 5.7 1500 would have MDS while the same year 2500 would not. What you need to find out is if a CAN bus (06-08) 2500 PCM would be compatible in your 1500; it was hit or miss in the earlier 03-05 applications when people were trying to use a factory PCM that would allow for a manual trans.
Same TC in the RFE for both the 4.7 and 5.7; not necessary to swap them unless yours is toast. The earlier years show differing p/n's for the different TC's but by 2006 it's just one p/n for all RFE applications.

 

[C L Martin]

I'm using the 04 throttle body & 04 cable & control box(under battery) to make it drive by wire. Donor is late 04 2500, so no egr. TC shows to be same part#. All interior controls on dash & steering (tow/od off, cruise etc) are identical. Already swapped heater box which was direct swap. I figured the 04 pcm might work better with 04 eng. harness although it will also plug into my 06 pcm. Either way it's got to be tuned for cam, headers & 10:1 compression. Not sure if there were any pin out changes from 04 to 06 on the harness that goes to interior, fuse box etc. That's the one that only has 1 plug to pcm. I want to get as much worked out as possible before I do the swap so I'm not down for weeks figuring it out.

 

[C L Martin]

I'll add, not worried if it throws a light as long as it runs. The 06 pcm can be changed to run a 5.7 but not sure that would work as well with the 04 harness, sensors etc.

 

[C L Martin]

Also, the early 04 had a different pcm like the 03. The late 04 pcm looks identical to my 06 for what that's worth. 4 plugs, bolt in the same, same plug ins.

 

[C L Martin]

I was told by tuner that my 06 pcm can be switched to 5.7 in the tune, which would probably require the 06 sensors & changing the plug ins on the 04 harness to fit the sensors if they're different.

 

[Michael blackmon]

Should be a pretty easy swap. Just use the 04 harness and either computer will work. They say the 05 up pcm is more tunable. You can send your 06 computer to solo pcm in Florida for the 5.7 update, then the tuner will do his thing for the mods. The 04 harness should just plug right into your firewall. I swapped a 02 4.7 ram to a 05 5.7.. with cam and such mods. Trans is the same. There are some good write ups on here about swaps almost right down to the last wire. They helped me a lot as I had a 03 donor truck and then had to re-pin the harness to upgrade to a 05 for tuning with cam and stuff