Just another M112 Thread


Active Member
So after seeing Mike going for some Roots and Nick suggesting that I buy an M112 adapter plate. I pulled the trigger on it and and got it.

Now I know a lot of people initially told me I was making a big mistake because there's no intercooling on the M112 and that I'm going to experience a huge amount of heat soak with the car but to be quite honest, I'm ok with it. You see, most people, especially on MM would constantly force down your throat to think ahead, think of the long term usage of the vehicle. What are your long term plans and build from there. Well I've done a whole lot of talking with WickedSnake and have his build thread read from start to finish (I actually subscribed long before he was started with his swap). The car will eventually be 4v swapped, so what better way to prepare than to buy the roots style M112 so I'll have it long term.

Onto the nitty gritty. I'm going to amend this first post so that everything I learn throughout and that which is posted further below is going to all get compiled up top here.

Required Parts:
Eaton M112
Adapter plate(available from mysteed)
39# injectors
90mm Lightning MAF
CAI for a 03/04 Cobra
255 or 310lph fuel pump
- IAT sensor - 9C1Z-12A697-B – Ford
- IAT pigtail - 3U2Z-14S411-JZA - Ford
NGK TR6 plugs
Idler pulley and mounting hardware
Serpentine Belt
Gauges (wideband AFR, Boost)
RTV gasket maker
Supercharger oil
- Supercharger oil - Xl-4 - Ford
- TB gasket - F7LZ-9E936-AA – Ford
- Plenum gasket - 9L437 – Ford
- M112 gasket - 9H486 - Ford

Socket set and ratchet
Wrench set
Tap and die set
Drill and assorted bits
Assorted pliers
Wire crimper
Extra wire, vacuum hoses, wire loom etc
Assorted nuts, bolts and washers

Build Threads:

- Fink's Installation thread - here
- Fink's build thread - here
- GDP's Build Thread (Fink referenced this guy a few times) - here
- Chaoticdismay build thead (GDP's references this guy several times and this is the guy with the shaker hood on the m112) - here
- 04nighrmare another guy who also did the swap - here

The two who started it all...
Matt - LilRoush - here
Nathan - mysteed while developing the plate - here

Just as any FYI... 3.7mustang.com is the best place to find a lot of this information.

I've compiled these install threads and instructions into a 30 page living document on my computer attached here...


I'm looking for any hints/tips/tricks/call outs that you guys have acquired and I'll post them up here with due credit. I'd also like to get a conversation going. Feel free to post pictures and contributing as such.

FAQs: (Under construction)

1. Adapter Plates:

There are several different kinds of adapter plates out on the market. There are (to the best of my knowledge and the people I've talked to) 4 variants of the adapter plates. Typically the adapters plates run from 700$ to 900$ depending on who is selling and what version they are selling.

- The height of my mysteed plate is 2.25"
- In order to prevent the Plate warpage that happens from the welding of the plate, mysteed would send his plates to a CNC place so that they did not exhibit the warpage. Below is a pic of my mysteed plate.

- Here is a pic of the design by LilRoush


SSM-Old Design:
- Here is a pic of the original SSM-Old Design Plate.

SSM- New Design:
- The height of the SSM-New plate is ~2.375"

The tallest height of the M112 blower is ~6.125" at the back where the plenum connects. The top of the stock pulley is roughly 5.125" from the top of the adapter plate. This would mean, if you're doing measurements off your lower intake you should be adding the heights above to whichever adapter plate you end up with.

Also, if you end up keeping the IAC in its stock location, you will be adding roughly 1.5" to 2" more to the top of the blower.

2. Hood Clearance:

Hood clearance is a well known issue with the M112 on the v6 motor. This has to do with the fact that the adapter plate adds height to the otherwise already tall M112 Blower. Many have tried several different methods of mending the stock hood as well as testing out different hoods with cowls. Remember this is all going to come down to which adapter plate you have.

With mysteed's adapter plate or ssm's newly developed adapter plate, it is my understanding that most cowl hoods including a 3" cowl or the cobra R will fit without rubbing to successfully cover the M112.

Stock 99-02 Hood with GT Hood Scoop
- Here is an example of the M112 under a stock 99-02 Hood with a GT hood scoop. As you can see it needed to be cut AND the hood scoop doesn't quite reach to cover the pulley.

- Here is another example of someone who tried to use the stock hood. As you can see the pulley sticks out once again. I've heard that there isn't a huge electrical issue with running this during the rain but because of the water you will be prone to belt slippage. With that in mind, this guy took it the next step.

Tork Tech Hood Scoop
- This hood scoop was designed and built to specifically reach farther and cover the M112 pulley. Now as far as which adapter plate this was intended to work with I'm unsure. It was designed for usage on the 2v motor but I've spoken with someone who actually used it.. However, if you can get this to work it may be a decent alternative. If you look at the images above. The blue mustang seems to have a smaller pulley on it which looks like it would clear the scoop while the red mustang looks like it has a larger pulley on the end of it which will not clear the scoop. The guy who used it said that with a little bit of saving from the poly and a 3.1 pulley (3.4 may fit but will be pushing it). With these you're also gonna need at least a 25% or 42% UDP.


Stock 03-04 Reverse Scoop Hood
- As you can see, the reverse hood has even less clearance since the hood is generally lower in the back and higher in the front. With the highest part of the blower in the back, this is one of the most unlikely hoods to be able to get working.

- Covered in snow, but you can see the clearance

Hood Cowl Modded
- In this pic, someone felt the need to mod a Cowled Hood. I believe that this was required because the owner was using the SSM-Old Design plate.

Mach 1 Hood Modded
- Chaoticdismay did an awesome job modding the mach one shaker system as a cover to his M112 giving the car the Mach 1 appearance.



3. Boost

- Stock Crank + 3.65 blower pulley = 12-14 psi of boost
- Stock Crank + Stock Blower Pulley has been run successfully if tuned correctly, but it is at the limit of what should safely be run on stock internals.

Some words of wisdom:
LilRoush - "Yeah, with stock crank pulley and stock Cobra blower pulley, you'll see safe boost.

With and OD crank pulley and a 2.8" blower pulley, I got over 20 psi on the 4.2L (according to the AutoMeter). That is a big no-no for stock motors."

RustyRodder (Alex) from 3.7
"...with a little bit of saving of the poly, and a 3.1 pulley (3.4 may fit, but pusing it). Obviously with these you will need a 25 or 42% UDP. With the stock lower intake (no porting), and stock manifolds/heads, a 2.93 pulley and 25% lower ran about 10.2psi on TomZacs car. But as you said, this all varies with the setup."

4. Non-Intercooled

- One of the main reasons that the M112 is not intercooled is because the intercooler on the Cobra sits *inside* the intake manifold on the 4v motor. There is not enough room in the adaptor plate for the intercooler to sit in it.
- Many would say, then why not make a lower intake to support not just the intercooler but even just to lower the m112. After reading on what lilroush and mysteed have mentioned, the problem is cost. The lower intake isn't just a place where the runners connect to the heads, but it also contained the cylinder head temperature sensors, as well as the cooling jackets that the coolant runs through.

Running the wideband in the rear o2 bung until you can get one welded in closer to the collector is alright. It can be run in either the drivers side or passengers side. It has been run in the drivers side to decrease wiring to the A-Pillar.
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You should make that write up a post in the How To section! ;)

cant wait to see you start this project.


Active Member
You should make that write up a post in the How To section! ;)

cant wait to see you start this project.

While I would like to do that, I don't think it would be fair to Fink to bring his thread here without his permission. Which is why I fully linked back to both of his threads from here. I am a monster when it comes to taking pictures so rest assured, when I DO get to the point where I will be performing the swap, it will be a complete write-up soup to nuts.


Active Member
Added a bunch of information and started separating it accordingly. Pictures will start to be added. Should I add the pictures as links or embed them right in the OP?


New Member
Nice thread man! And gotta get a lot of pics in this lol and this is really well laid out with the info you supplied...good job!


Boosted V6
You got a nice cam to compliment the blower? Also you should check out how the sc guys are converting whipples and autorotors to their cars by inverting them. This would be the route I'd HAVE to take just to be able to intercool it.


Active Member
Lots of good info here!

One thing I haven't seen yet is if anyone has tried a 03-04 cobra hood with the smallest adapter plate to see what kind of clearance is there