03 2003 1500 5.7 hemi swap with 2010 5.7 l hemi

I'm new here, and i'm in a pickle and looking for some resolution, if anything is possible.
My 2003 1500 blew up when my room mate ran it out of oil. I gave a wrecker my vin and had a new engine delivered.
After installing my injection coils i noticed the harness showed it was a 2010 5.7 hemi. Obviously the wrecker made a mistake, but i have a three weeks of time installing, and i want to see if i can make it work. one week of installation and two weeks of troubleshooting this curfuffle and i'm stumped.

so heres what i've done.
the wiring harnesses for engine injector coils didn't match so i spliced my 03 male end onto the exisiting 16pin wiring harness.
Plugged into computer and no codes show.
Engine appears to be wired correctly.
I have fuel pressure and spark to each cylinder
When starting the truck sounds like it wants to run, but as soon as engine rpms exceed that of the starter the truck dies.
Timing is probably out, but how can i change timing?
i realize the 03 pcm or ecm might not recognize the '10 engine. Is this swap possible. i have done everything to my knowlege. I don't know anything about these computers. Will a 2010 pcm install work? is there a delete kit i could use?
anything i can do to make this engine work ? HEEEELLLLPPPP

Dude lol.....no. You have a completely different engine. Your basic 03 5.7 was fairly simple. The engine you're trying to put in has variable valve timing (VVT) and MDS (and active intake if you tried to use the 2010 manifold). Other than the heads, nothing is really compatible between the two engines. Your electrical/computer system in your truck is PCI bus, the one you're trying to use came out of a next gen CAN bus truck. The only possible way you could get this to work is to try to adapt the correct year PCM with a very altered harness. The computer would be confused because your exhaust configuration doesn't match a '10, plus I'm guessing you tried to bolt your stock intake manifold to the eagle heads, which means you will have vacuum leaks as well as not having the SRV from the '10 intake.

Thanks for the speedy response
i called the wrecker this morning and it IS a 2004 engine.
The 2010 wouldn't actually bolt on exisiting engine mounts.
the wrecker is currently looking into why there is a 2010 spark plug/injection coil harness, that was installed when i recieved the new engine.

I have the 03 harness now installed, but due to year/mod, i'm missing the egr harness.
i guess i'll have the flash the ecm, so it'll recognize the new engine?


Like i said, have spark, fuel pressure and the engine was dyno'd so i know its good. . (after a hell of a lot of running around and research)

because it's still a third gen engine, this should work eh?

Gold Papa said:

Thanks for the speedy response
i called the wrecker this morning and it IS a 2004 engine.
The 2010 wouldn't actually bolt on exisiting engine mounts.
the wrecker is currently looking into why there is a 2010 spark plug/injection coil harness, that was installed when i recieved the new engine.

I have the 03 harness now installed, but due to year/mod, i'm missing the egr harness.
i guess i'll have the flash the ecm, so it'll recognize the new engine?


Like i said, have spark, fuel pressure and the engine was dyno'd so i know its good. . (after a hell of a lot of running around and research)

because it's still a third gen engine, this should work eh?

Click to expand...

Ok, lemme see if I got this right, turns out you actually got an 04 engine, but it has 06+ coil setup? 03 doesn't have EGR, you'll need to block it off. 03 and 04 engines are virtually identical except for the EGR, so you don't need to flash the PCM to run the engine. Check your ASD relay, if that's tripped for any reason it won't start. Also you said earlier you modified your harness for the later coils?

A 5.7 regardless of 2003 to 2010 is the same identical block as far as mounting. However the tone wheels for the cam and crank are completely different. And then the EGR issue. I just converted my 03 ecm and TCM over to an 05 system with great success. You have to be careful with the engine swaps. Anything pre-2009 will work in the 03-09 trucks because of the cam/crank wheels. Other than that, you'd need and new harness,ECU and everything. It's a pain


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Thanks fellas.
Ya, as crazy as it sounds i have an 04 engine with the injection/plug harness from a 2010.
i just ordered an original 03 injection/plug harness, so we'll see if that works over the weekend.
checked my asd relay awhile back after reading people having a "no start" issue. Everything looks to be ok.
My next question for you guys would be, my ecm, timing should work? Between the 04 engine and the 03 truck? Have you guys heard of any issues?
Will write a reply once i install the 03 harness on the 04 engine.

As long as you have the 03 computer and harness complete and intact, it will run an 04 engine, just don't forget to cap the EGR port (03 doesn't have EGR).