I want to install a 318 magnum EFI and 518 overdrive into a 1974 challenger

[lil stinker]

I am looking for some help, input, and advice on a project I am going to start on this winter. I have a 74 challenger that has been a dragstrip car for many years. Interior and dash is all gone. I am wanting to keep this low budget as possible by using parts that I have. I want to put a 318 magnum (from a 93-2001 ram or dakota) and 518 overdrive as the drivetrain. I would like to keep it electronic fuel injection. But, I may have to go carburated if I cant get enough details on how to do it correctly. Surely there has been someone or a magazine out there who has done this. I do have the dash frame and pad(VIN), steering column, and brake pedal. I am wondering if I can use the heater core/A/C box out of a dakota. As you can tell, I want to update it some. I do have a challenger instrument cluster, but I might use newer guages (like intrepid or R/T dakota). I dont have any wiring for the car, unless I use the dakota wiring(may have to buy this item to fit my application). My email is andysbsp@yahoo.com if your reply is lengthy. Thanks!

[jimynick]

This is a big job and will require many skills- mechanical, electrical and body, so you should ask yourself if you're up to it, first. That wasn't meant to be insulting, just factual. To retain FI from the donor, you'll have to modify the fuel and wiring extensively and the odds of the donor's wiring working in the 74 range from slim to none IMO. There are aftermarket harnesses you can buy and have tailored to your application. I believe there are trans tunnel mods to be made as well as the previously mentioned wiring and plumbing as well as resizing the drive shaft and so on...
  I believe there are threads on here devoted to this swap and it HAS been done, but for my 2 cents worth, stick the 318 in and either do the mods required for the OD trans or buy a Gear Vendors OD unit and save a lot of cussin'. You should be able to get an oem harness from someone on this site should you choose to easy way. Good luck, oh and, welcome to the site. The boy's will be on you for photos of the old girl, so get ready! 

[lil stinker]

 There is a lot of information that I can use on this website. I have been doing bodywork for 28 years, so the sheetmetal and structural modifications dont bother me. If someone has done this swap to their mopar, I sure would like to hear from them to make my adventure go smooth. Basicly, I think I can use a wiring harness from a 92-95 ram or dakota, install electric fuel pump, fuel lines and regualator, modify the 518, driveshaft, and crossmember as described on this website for the most part.

[Chryco Psycho]

Check with Bouchallon sp or Mancini I think they have a computer for this swap

[PlumCrazyChris]

There is a lot of information on here about this swap, especially the 518/500 swap.  Check out this one for more info on it.  The good thing is that with a little trimming on the case, its just a bolt in.  You just need a custom crossmember, but that doesn't sound like a problem for someone with your skills. 

I have one in my car right now.  I just need to finish up the wiring on my 5.7 and I'll have it on the road.  Its getting exciting . 

I had planned on a 91 TBI 318 in mine, thats a pretty straight forward swap.  Hotwire makes a conversion harness for that swap using the factory computer.  The harness isn't cheap, but I think it was cheaper than mine which was ~$1000, but they are the only game in town as far as I could find. 

Keep us posted on how it goes and let me know if you need any help with the trans.  It is a challenge, but it will be sweet too . 

Chris

[PlumCrazyChris]

I forgot, here is a link to the 518/500 trans swap thread.

http://www.cuda-challenger.com/cc/index.php?topic=23678.msg840646#msg840646

[rockymopar]

If you think you might go with a carb, go with a 95 or earlier, as the trans on post 95 is computer controlled.  I would still choose a 95 or earlier if you will go injected as the later ones used an electronic speedometer. Mopar performance actually made a pretty good ECU for the earlier trucks, though premium fuel is required. As for me, I have a megasquirt injected 5.9 with an A518 and can say the work is worth the result.

[Super Blue 72]

Just first want to say I have no experience with this but I was wondering why stay with a 318 and not a 360?  Aren't there any 360 FI engines out there?

[rb70]

If you think you might go with a carb, go with a 95 or earlier, as the trans on post 95 is computer controlled.  I would still choose a 95 or earlier if you will go injected as the later ones used an electronic speedometer. Mopar performance actually made a pretty good ECU for the earlier trucks, though premium fuel is required. As for me, I have a megasquirt injected 5.9 with an A518 and can say the work is worth the result.

I just did the swap for my chargerand you want a 93-95 46RH tranny, as it is hydraulically controlled. 96 and up are 46RE and they tranny is controlled by a computer, while 92 and alder 46RH's do not have lockup. It is not a hard swap and PATC has a kit to make the swap easier.

[PlumCrazyChris]

They are out there, but I'm sure this is just a case of run what ya brung.  Nothing wrong with a 318 if you don't plan on racing it, might even pick up a few mpg.

[ShelbyDogg]

The magnum 5.2 or 5.9 in and older car is very easy to do. First of all, drop a regular electronic ignition distributor in and run a mopar electronic control unit. Second, get a FAST EZ-EFI multiport conversion kit:

 http://www.ebay.com/itm/FAST-302000-Multiport-Retro-Fit-EZ-EFI-Kit-/251168451405?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a7ace6b4d&vxp=mtr

for $870, and you now have a running engine after you plumb a fuel pump and return line.

Third,  Get a 4 speed setup and throw that in there.   

I was thinking of Magnum engine in my Cuda, but like the sound of a HEMI-Cuda name better.
I have three of theses EZ-EFI computers now.

[PlumCrazyChris]

For the OD trans swap, the only thing that is custom is the tranny crossmember.  You can cut up your stock one, or build one from scratch.  I have a template I cut out with a water-jet, all you do is fold on the dotted line and bolt it together, no welding required.  Let me know if your interested.

Chris

[autoshopguy]

We will be doing this to my 70 challenger.  I decided to go with a 96(97 ram will also work stay away from the 97 up dakota and 98 up rams they start to get a little sensitive although with som work may run the dash yhou want better) computer and matching harness mainly for the aftermarket tuneability.  The OBDI 92-95 has no aftermarket support, the Mopar Performance is still available for OBDI and does a pretty decent job keeping up with mods(have one in a 95 dakota w 360 that runs 13.3s @104mph and 3750lbs).  If you are swapping the entire harness I would also look into fitting the steering column out of the truck which should make hook up simple.  The 46RE (96up) trans is about an inch shorter in 2wd form than the 518(aka 46RH 90-95), this is because of the lack of mechanical governor system in the RE.  The 46RE is fully computer controlled while the 518 is hydraulic controlled 1-3 with electronic controlled 4th and lockup so the trans will need to mach the computer system you end up using.  I will be trying to document the swap in mine a little but likely won't be starting that for a while. 

On a side note at one point I was getting a consistent 23MPG @75-80mph in the dakota with the 318 and mild mods.  The best I saw in the exact same truck with a 360 swap(same cam and everything else as 318) was 19MPG the current 360 will only pull 17MPG max.  I'm expecting 22-26MPG highway with the 318 in the challenger (lighter and less brick like aerodynamics).