Have some questions about a 5.7 swap into 73 Charger

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Montclaire

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Hello, I know this is an A-body board, but this seems to be THE place for 5.7 swap info, so I figured I would join and ask a few questions. I have looked through several posts on here, so really I'm just trying to put everything together in my head and seek a little guidance.

Let me say that I am not looking to upgrade the motor, the K-frame, or the chassis beyond any factory variation. The point is to get the reliability of fuel injection and 50-state parts availability on the motor. I will be using a small block 727, and would like an in-tank fuel pump. Brakes will be manual but I would like to keep the power steering; the later Bs should have some more room in the engine bay so I don't think it will be a clearance issue.

I know I can get spool motor mounts, so that's good to go. For the motor itself I'm looking for an early truck hemi as that will mate up with a cross flow radiator similar to several mid 70s chrysler offerings. I want to keep a clutch fan instead of electric, I did see this done in a magazine article, so that's a go as well. I'd like to use a factory looking airbox, maybe one off a jeep wrangler or similar, mounted where the battery would be (I'll relocate to the trunk).

For exhaust I am looking at the Jeep (non-srt) mainfolds which I can only guess will clear. I do not want to buy headers. If they are cheap and work that is fine with me. Is anyone selling H-pipes with an O2 bung to mount up to these in an older mopar? There are several choices for oil pans, so that's no problem, and I know of the 45' offset adapter for the filter (or just use a hockey puck type?). From what I have seen I can use an eliminator pulley to get rid of the AC compressor and a power steering kit to adapt the pump for the older box.

Now the fun part, wiring. I have seen the S&P harness, are there other options out there that would work just as well but save me a couple bucks? $1300 for a harness seems way high. I believe that I still need a factory computer with that, does it have to be for a manual? Also, from what I understand, I can use either the early or later drive-by-wire pedal setup, but it's only the earlier one that will give me the cowl switch unit which will allow me to use a trans kickdown. What about the alternator, is the output too high? Do I need to regulate it some how, or will it use the stock 73 regulator already in the car? What about my dash gauges? How much splicing do I have to do to connect up to my factory ignition, charging, and power leads?

What are my options for a fuel tank? Does anyone offer repop tanks with a built in pump or modified sending units? I have seen the corvette filter piece that S&P offers so that you do not have to plumb a return line. I know for the trans I need a special flex plate and a non-weighted converter. What application would I be looking at for a non-weighted converter with a stall speed suitable for a mid 70s b-body?

What did I miss? Thanks
 
I didn't know that the MSD Hemi-6 will work with EFI, I thought it was just for carbed engines. At around $550 for the controller and harness, is there any reason to use the S&P unit vs the MSD? The engine will stay stone stock for quite some time. Thanks
 
I'll take a stab at a couple of these Q's.

Montclaire said:
I know I can get spool motor mounts, so that's good to go. For the motor itself I'm looking for an early truck hemi as that will mate up with a cross flow radiator similar to several mid 70s chrysler offerings. I want to keep a clutch fan instead of electric, I did see this done in a magazine article, so that's a go as well. I'd like to use a factory looking airbox, maybe one off a jeep wrangler or similar, mounted where the battery would be (I'll relocate to the trunk).

For exhaust I am looking at the Jeep (non-srt) mainfolds which I can only guess will clear. I do not want to buy headers. If they are cheap and work that is fine with me. Is anyone selling H-pipes with an O2 bung to mount up to these in an older mopar? There are several choices for oil pans, so that's no problem, and I know of the 45' offset adapter for the filter (or just use a hockey puck type?). From what I have seen I can use an eliminator pulley to get rid of the AC compressor and a power steering kit to adapt the pump for the older box.

Now the fun part, wiring. I have seen the S&P harness, are there other options out there that would work just as well but save me a couple bucks? $1300 for a harness seems way high. I believe that I still need a factory computer with that, does it have to be for a manual? Also, from what I understand, I can use either the early or later drive-by-wire pedal setup, but it's only the earlier one that will give me the cowl switch unit which will allow me to use a trans kickdown. What about the alternator, is the output too high? Do I need to regulate it some how, or will it use the stock 73 regulator already in the car? What about my dash gauges? How much splicing do I have to do to connect up to my factory ignition, charging, and power leads?

What are my options for a fuel tank? Does anyone offer repop tanks with a built in pump or modified sending units? I have seen the corvette filter piece that S&P offers so that you do not have to plumb a return line. I know for the trans I need a special flex plate and a non-weighted converter. What application would I be looking at for a non-weighted converter with a stall speed suitable for a mid 70s b-body?

What did I miss? Thanks
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Skip S&P for the harness.......and well really for the rest of it too ($$). HotwireAuto makes (or use to anyway) the harness for S&P.

Dave Weber of ModernMuscle can get most if not all the parts for very reasonable for ya. I got my EFI tank parts from him. Yes the corvette regulator doesn't need a return line (I posted a pic of mine). Dave sells stock style tanks already done or parts to do it yourself. He has a bunch of his stuff on Ebay.
 

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Wow, nice tanks. That is what I would be looking for.

The harness is still high, I'm trying to see what the advantages are over the MSD unit. The MSD looks to be a lot less comprehensive, so I don't know if I would have to combine it with the factory harness or what.

I'm figuring 4k plus the engine to do this, sound about right?
 
Yes, the Jeep 5.7 Manifolds "should" work, they will definitely fit in an A-body, so the "should" fit in a B, body.

As far as using the factory wiring harness.

How much time do you have? How comfortable are you with an ohm meter and a manual? Do you know someone who works at a Dodge/Chryser dealership?

Here's the low down on the Hot Wire / S&P Wiring harness.

The Factory computer has a built-in anti-theft device called a SKIM Key. Basically the key has an embedded chip that talks to the computer, similar to an RFID (Radio Frequency Identification Device) tag. When the key gets within a few inches of the ignition switch it begins to talk to the computer saying, "I am authorized to start this engine." Thus, when you turn the key, the computer sends power to the coils and to the fuel pump which allows the car to start.

This is why it is CRITICAL to get the VIN number out of you donor car. The VIN number is essentially the combination to the computer. The dealer is able to use the factory service tool, to trouble shoot a variety of engine problems. Think OBD scanner on steroids but they cost 4K. (Ouch!!) Hot Wire et al, use their factory service computer tool to enter and disable the SKIM key feature in the computer. They charge a couple of hundred dollars for this service. If you know the junk yard your getting the motor out of and can get both the keys, ignition switch, and wiring intact you can "PROBABLY" use the factory skim key, and related wiring without reprogramming the computer, other wise you'll have to pay someone to re-program the computer.

The Next thing that Hot-Wire does is set the transmission. If you are using a purely mechanical/hydraulic transmission like the 727/904 they change the computer settings to that of a manual transmission. This is why the your transmission choice is so important. If you later choose a late model trans, you'll need the automatic transmission harness AND a reprogram to enable the transmission control feature. All 2004 and later use a single computer for both engine and transmission. 2003 models used a separate transmission controller. If you plan to use a late model transmission the truck transmission is the preferable option as it has the speed sensors built in while the car transmission relies on speed sensors in the wheels making the swap more difficult.

The next issue, is one of relays. The hot wire harness comes with a series of relays to facilitate the transplant. The big selling point of the Hot-Wire harness is the fact that you only need to hook up four wires. If you decide to not use their harness you will need to install a number of relays for things like the fuel pump, the computer itself, and the coils. Some have used the factory relay box from their donor vehicle.

So if you decide to forgo the Hot-wire harness you will need to do the following:

1. Get a factory service manual for your donor vehicle. Service manuals are often available off of ebay for $20.00, this manual is critical if you plan to modify the factory harness.

2. Read and re-read the service manual, particularly the portions dealing with the power center and the anti-theft devices. This reading will help you determine which wiring harnesses you need beside the engine harness.

3. Get the VIN # off your donor vehicle.

4. Get as much wiring as you need or can get from the donor vehicle.

5. You'll need a tiny screwdriver or pin removal tool. The factory service manual gives SPECIFIC instructions on how to remove the pins from the connectors. The service manual also gives SPECIFIC instructions on how to CORRECTLY probe the plugs to check for continuity.

6. You'll need to trace each wire within the harness. Clearly some will be removed. For example, there is a couple of wires going to the A/C compressor, if you are not using this you will simply discard them. The factory computer controls a large number of functions that you will not be using, so eliminating them from the harness will go a long ways toward cleaning up the engine bay.

7. You'll need to plan your power center. The ignition switch should NOT be used to supply all the power to the computer, you want to use a relay. The computer draws quite a bit of amperage, far too much to run through the key switch. Again you'll also need relays for the fuel pump and the coils.

8. You'll need to decide how to handle the Skim Key. Either you'll need the dash wiring, and or you'll need to send the computer to someone like Hot-Wire, or if you know a tech at a dealership. If you think, Hey, I'll just buy a used scan tool from off of ebay, they should be cheap with all those dealerships going out of business, Good luck with that, there are two on ebay right now, the first is 2K and the second is 4K and that is WITHOUT the card used with each vehicle. OUCH.

If this seems daunting, don't despair, it's all about being methodical and planning. Keep in mind that what Hot-wire is really selling is knowledge. The more knowledgable you become, the more informed your decision will be.

Hope this helps,

Regards,

Joe Dokes
 
For gauges to work a friend did his by using tee fittings for oil and water sending units leaving original for PCM and adding old style sending units to drive the gauges.
 
Yeah, from what I'm reading it looks like the full harness is just the way to go. I can do basic wiring but I don't feel like spending the next 6 months butchering a donor harness.

Ok, so if I get the hotwire harness, I need to send them a stock computer which they will reprogram for the 727. I would need the VIN for whatever the computer came out of, and not the engine, correct? And since I like to make things difficult, can Hotwire supply a new, re-coded key (or even just a fob) so that I can keep the SKIM feature? It's an awful nice theft deterrent...

As I said it seems as though I can use the factory APPS which will provide me a hook up for the stock pedal cable and a way to mount a trans kickdown. From what I can tell these used in 2003 (maybe 04?). The revised pedal assy would work as well, but with no kd. What you're telling me about the computer situation for 03/04 has me thinking - can I get the APPS, with the single 2004 computer, and a harness to match (or if it's a 727, it doesn't matter, because the 03 computer isn't going to control it anyway)? I'm sure there's an answer, I just need to know what to source.

Oh, and is there a height issue with the accessory mounting on the early truck motors?

Thanks for the help so far, there's quite a bit that goes into these swaps.
 
Just a few comments on the wiring.
I modified the stock wiring harness myself and have the engine running.
Patience and attention to detail was the key to success.
I did not need special tools. It is pretty much just cutting and splicing. The service manual is your bible to identify the correct wire and circuit. Once you do that you just decide if you give it power, ground it, not use it, or connect it to the correct input or output. You will need to use relays for some circuits and use appropriate fuses for others.

Not all computers have the SKIM. My advice it to find one witout it. If you want to keep the SKIM you would also have to set up a sensor where you put the key in the ignition or use the steering column from the donor vehicle.
VIN is locked to the computer.
 
I have a truck front cover setup in my Dart and haven't seen any clearance issues, so I imagine a Charger would probably be okay too, though I can't really say that for sure.

For exhaust you might see if stock LX manifolds will fit. They almost fit an A body, so a B body might have enough room and they come with O2 bungs already from the factory, so that might save you from having to put others in somewhere else.

The MSD is nice and fairly easy to work with, but if you want to run fuel injection and a stock computer you're better off just using the stock stuff because you'd still need a harness and computer to run the injectors (MSD is timing only) and the pigtails to split the cam and crank signals so both computers can read them. You could go with an aftermarket fuel injection computer (I and several others are going with a Megasquirt setup), that could potentially save you the money on the wiring harness, but it's pretty intensive getting it all set up because you pretty much start from scratch with them.
 
The car front cover and intake don't fit as well as the truck front cover and intake. I know in an A body you need to notch the frame rails for the alternator on the car motor.

Riddler
 
When I have more time (tonight) I'll give you my input, but I have everything you need for the swap. I have a factory 04 harness the apps box, 2 pcm's (one from a 2500 manual trans and the other from a 04 1500 auto trans) ihave the fuse box, all under dash wiring, you name it. It all came out of my 04 ram that was totaled. (woththe exception of the 2500 PCM) I know for a fact the 1500 PCM does not have SKIM I don't know on the 2500. I even have the service manual on PDF that I would include. Everything can be had for $800 plus the ride. And if there is something you needlaterthats not included (highly doubt it) I'll get it for you free of charge. (assuming it's a stock wireing part or something not included in the kit)

Reason for the sale is that I don't need it. The motor I'm building will be well outsidethe factory computers abilities, so I'm going with mega squirt. If your intrested let me know and I'll pull it all out and snap some pics this weekend.
 
The truck stuff wont need to be changed to fit in any b body, although the car set looks more pleasing to the eye. Check my thread over on fbbo, late model hemi into early b bodys, it's in the 62-65 section. And just incase your wondering about the year differences, dont, all b and e bodys use the same front set up with minor changes from the factory.
 
Hotwire for the harness, they will also sell you a new computer already flashed for your app. You should consider swapping to a 545rfe trans, it is a 5 speed fully electronic and will help give you excellent fuel mileage, 20+ mpg. Rock Valley will make you a tank with fuel pump installed. This is not a cheap swap, your probably looking at 6-7K all finished.
 
5.7 hemi said:
The truck stuff wont need to be changed to fit in any b body, although the car set looks more pleasing to the eye. Check my thread over on fbbo, late model hemi into early b bodys, it's in the 62-65 section. And just incase your wondering about the year differences, dont, all b and e bodys use the same front set up with minor changes from the factory.
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Wow, what a thread. I noticed that you said you swapped to a car intake and added 6.1 injectors. Is there anything to gain from that with the factory computer? I didn't see you mention any other type of tuning device, but I may have missed it, it's a long thread.

Hotwire for the harness, they will also sell you a new computer already flashed for your app. You should consider swapping to a 545rfe trans, it is a 5 speed fully electronic and will help give you excellent fuel mileage, 20+ mpg. Rock Valley will make you a tank with fuel pump installed. This is not a cheap swap, your probably looking at 6-7K all finished. 10-25-2011 11:44 AM
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I would consider the 545rfe but I do not want to hack up my trans tunnel and x member. The Modern Muscle tanks are beautiful, I'll either buy one finished or buy the kit and DIY (DIM?). I'll have to give them a call and see how much modification the kit requires (if any).

When I have more time (tonight) I'll give you my input, but I have everything you need for the swap. Everything can be had for $800 plus the ride.
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Thanks, I'll let you know once I see what I get with the donor engine.
 
I posted a response but it said it was holding it for mod review, I don't know why, but please check back later, I did reply here.
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Tin, are you saying 6-7k plus the motor, or 6-7k with everything? I'm not above a little JY digging or parts shopping so I'm hoping to keep it a good bit lower than that. There's not much wiggle room on the mounts, the pan, or the harness that I can see, but the rest is up for bargaining. Some of the mopar stuff I'm finding at a real deep discount.
 
If your in no rush I'll be able to fab a tank about June 2012. As I'm buying a CNC plasma cutter in may. It will be capable of cutting and TIG/mig welding when I get it all set up.
 
With the 1.5 inch spacers between the intake and heads I figured the stock injectors didn't flow enough, besides the 6.1 injectors I found for dirt cheap new. I'm using the stock computers and have a Hypertec tuner (looking to get a diablo), and a plus to using the factory stuff, if I ever have a problem any dealer in the country can download and also do updates.
 
Don't know what the other gas tanks run price-wise, but Hot Rod City Garage makes tanks with in-tank pumps options as well I believe. There's a guy here in Kansas that offers them on his website (www.themopardude.com). An in-tank pump setup runs around $750-800 for a brand new aluminum tank and pump. You can get other options on the tank as well to tailor it to your specific build. I was looking into that when I swap back to fuel injection because I just didn't want to deal with the headache of trying to modify my current tank, and the guy lives less than 100 miles away, so it's convenient.
 
Montclaire said:
Tin, are you saying 6-7k plus the motor, or 6-7k with everything? I'm not above a little JY digging or parts shopping so I'm hoping to keep it a good bit lower than that. There's not much wiggle room on the mounts, the pan, or the harness that I can see, but the rest is up for bargaining. Some of the mopar stuff I'm finding at a real deep discount.
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Good used motor 2500-3000
Fuel tank 800
Harness 1100
Computer 600
motor mounts 200
headers 700
2 O2 sensors 100
Misc stuff 500
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$7000

Plus I'm sure there is stuff I'm missing, like a radiator, hoses, air intake, etc...

It adds up quick..
 
Montclaire said:
Ah. Any idea what year they started using SKIM?
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It is a security option and doesn't depend on the year. I think it is more common with Durangos and higher trim level 1500s and less common with lower trim levels or 2500s.
 
Tin Cup's is right, this is not a cheap project. But I think in the end it is well worth it as you get a modern motor with fuel injection. The key is planning. If you find a junk yard that will throw in a lot of the under-hood and under-dash wiring than along then figuring out the wiring is just a matter of being methodical. Otherwise, spend 1,700 on a harness and computer from Hot-Wire and have the thing running in a week.

For me, I have very limited financial resources, so figuring stuff, rather than buying solutions helps to keep the project moving forward by keeping costs down.

I think you ought to give 03 Ramit's offer some serious thought. It sounds as though he has everything you need. That being said it does depend upon what you get from the your pull out. Some yards don't care that much about wiring and will include a lot in the process of selling a motor. Others try to nickel and dime you to death. So depending upon what the yard wants Ramits offer might be a very nice deal. Especially since he has the under dash wiring.

The other really big issue is how stock do you plan to keep the motor? If you plan to hot-rod it a lot you might want to consider a stand alone computer like the AEM, FAST, or Megasquirt. Megasquirt is by far the cheapest, but it also has the steepest learning curve.

The big downside of the factory computer is that, if using the stock computer it is not yet possible to control ALL the engine management issues with an aftermarket hand held tuner. Thus, big cams, blowers can make tuning a challenge. Not to speak for 03Ramit, but this is probably why he's going aftermarket on his twin turbo project.

Regards,
Joe Dokes
Joe Dokes
 
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