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4.7 To 5.7 Hemi Conversion?

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Old 08-10-2015, 05:23 PM
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4.7 To 5.7 Hemi Conversion?

  #11  
Old 09-13-2009, 04:39 PM
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nevermind.. not gonna get involved
 
  #12  
Old 09-13-2009, 04:48 PM
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Originally Posted by Docwhitley View Post
When doing an engine swap like this will it still pass emissions? I thought that there was something to do with the computer or the engine had to be available for that yar or something like that... or is that a state to state thing? Anyone know?
Yes as long as you have all the factory parts that belong on the engine as well as the proper ecu programming. Usually the dealer can reporgram a 4.7L ecu to a 5.7L with the starscan tool. If not, the ecu's aren't much off ebay.

I had a mustang GT w/ a 4.6L SOHC engine that i pulled out and swapped for a Cobra 4.6L DOHC and passed NYS emissions inspection.

All the emissions parts I had removed were turned off in the custom tune I had written, which fools inspection stations by saying everything is good.
 
  #13  
Old 09-13-2009, 11:18 PM
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its definitely a state to state thing. here in SC we do'nt even do emissions tests anymore, quit doin em over 10 years ago. only rules are DOT approved tires, headlights below 54" and above 22", supposed ot have cats on (but nobody does), and as always, BUCKLE UP!

but as far as most states go yes, there are restrictions on what you can do.

OP, i'm looking into this alsi, i'v just killed my 4.7, i tihnk the tranny is the same if you have the auto but i'm not 100%, i would imagine a radiator harness, and maybe motor mounts? not really any info on it anywhere, just see as you go i guess.
 
  #14  
Old 07-29-2010, 03:56 PM
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Are you still thinking about doing this swap ?
 
  #15  
Old 01-27-2012, 12:12 AM
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I'm considering doing this. I have a 2003 4.7 and I want to swap to a 5.7 Hemi. What all do I need exactly?
 
  #16  
Old 01-27-2012, 08:31 AM
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There are some threads on this forum that can help you out.
First thing I would recommend is to get the complete wiring harness with the motor you buy , Including Power Distribution Center , ECM and even headlight harness..
After you get the 4.7 removed , you'll have to cut the old Motor Mount perches off the frame..You can remove the transmission with the motor and set trans. and 5.7 back in after the wiring is done , or leave the transmission in . Either way you'll probably have to put the motor in without any mount perches..Once the motor and trans, are lined up and where you want them you'll have plenty of room to weld the new perches back in and tighten up the Motor mount bolt..It's not too bad , I did mine by my self in less than 2 months.. The Dakota took almost a year . But I started out not knowing one single thing about Dodge wiring and everyone I talked to about it said it can't be done. It won't work. That thread is Dakota Hemi Swap with Pics..Pics on 1~4..8~12..Ram swap on , "2002 Ram Get HemiDaks 5.7 Hemi"..
BTW~ When you start searching for you're motor , The best years for swap are 03~05..
 

Last edited by HemiDak-Quad; 01-27-2012 at 08:49 AM.
  #17  
Old 01-27-2012, 08:47 AM
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I was just back reading this thread .
There are more "Good" reasons to replace the 4.7 with a Hemi than Bad..I've seen people with blown 4.7 motors try to find one used in good shape at a good price..It's shocking that such a motor is so expensive and hard to find in running condition..
The 5.7's are cheap and easy to find..I would never recommend doing a 5.9 to Hemi Swap..But I would rather have a hamster in a wheel under my hood than a 4.7..AND any one who thinks it would be cheaper to upgrade a 4.7 to get more H.P. than a Hemi swap , Needs to look into it a little..Everything performance for a 4.7 cost twice as much as a regular Motor."Just had to say it"...
 
  #18  
Old 01-27-2012, 10:15 AM
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Originally Posted by HemiDak-Quad View Post
First thing I would recommend is to get the complete wiring harness with the motor you buy , Including Power Distribution Center , ECM and even headlight harness..
After you get the 4.7 removed , you'll have to cut the old Motor Mount perches off the frame..
You shouldn't need to cut any engine mounts. Mine were bolted on. I removed them and bolted up the 5.7 mounts, no prob.

If you go to a 2003 5.7, no need for the fuse box either (power distribution center). Actually, I wouldn't worry about getting the pdc anyway unless you can get all of the body wiring that is in the 5.7 truck. Depending on the year you would still have the possibility having to run wires through the firewall.
 
  #19  
Old 01-27-2012, 01:06 PM
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No~one makes a good SuperChip , or power programmer for the 03' models that can change shift points and other important motor options. The 04' has a few, but The 05~up has the most when it comes down to performance..
I didn't use Hemi motor mounts on my swap I used the mounts off my 4.7. That's why nothing lined up. BUT the reason I didn't use Hemi mounts is because they didn't look like they would work without cutting anyway..My truck is an 02', I don't know if there's a differants between 02' and 03' Mount perches, But T-Muns is probably right. I have done two Hemi swaps and I could write a book about all the things I still don't know, But it was fun learning the things I do..
Funds kept me from doing anything the easy way . I had to make my harness , my mounts , and use parts off my wrecked Dakota..
Since I was one of the first to do a Dakota Hemi Swap , I didn't have the luxury of being able to ask someone. But with the swap you're doing , you do , and there are plenty of people on this sight that will help . Like I said before , It's not as bad as some people make it sound..You can do it..Just post plenty of pics...
George..
 
  #20  
Old 01-28-2012, 08:34 PM
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T-MUNS , Haven't heard from you in a LONG Time.. you get those 04 wires figured out ? I
m having problems with mine. I can't find the wires under the dash that controls the A/C condenser Fan Relay , My Dome light wire , or a/c compressor wire..The 04' PDC Harness and the 02' dash harness don't match all the wires it should. If you're putting a 04 Harness in an 02' truck maybe we can help each other..
 

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