1997 Mercury Mountaineer 5.0 in a 1991 Mustang. Will this work? | Ford Explorer Forums - Serious Explorations

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1997 Mercury Mountaineer 5.0 in a 1991 Mustang. Will this work?


New Member
October 13, 2010
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City, State
Little Rock AR
Year, Model & Trim Level
1997 Mercury Mountaineer
Ok so i have a 1997 Mercury Mountaineer with a 5.0 (302) motor. The Truck was wrecked from the back and totaled out.. The 5.0 is in great condition, and i dont want to get rid of it. So I've been looking around for a 88 to 93 mustang that needs a motor. I found a 91 with no motor for $500 the other day and im very interested in getting it. The only thing holding me back is that i dont know if this will work how i want it to... My main problem is the computer. My mountaineer is an all wheel drive and the computer is set up for that. The mustang computer is set up for the stock 5.0 HO heads with individual coils, which on the mountaineer the heads are gt-40s with normal plugs i believe. so in order to run the mustang computer i would have to change the heads and i want to avoid that. does anybody know what i could do by leaving the mountaineer motor stock without changing a bunch of stuff?

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The fox body Mustangs never came with individual coils. You'd either have to convert it to distributor or, I believe, you can buy a driver kit that allows the Mustang computer to run individual coils.

everyone on the planet with a 5.0 mustang is doing this...i've personally converted three already...

if you ditch the cam and valve springs for a good aftermarket cam such as a tfs 1 cam, you'll make 240-275hp at the wheels, or 300+ flywheel.

all that's needed for the conversion is the mustang oil pan and timing cover and accessories..then ditch the obd II stuff and retrofit it back with the dist from the fox mustang and it's computer...it's a straight up swap. If yours has the gt40p heads, you'll need the ford racing headers or mac headers to clear the different spark plug angle

v8only's right... It's an easy swap.

My Mustang:


The only difference is that I was running Speed Density vs. a MAF system in my '88.

Just run the stock Explorer intake- you'll be plugging some ports for accessories that ran off it, but it's easily doable.

Hey I have a 92 Explorer and im looking to do a 5.0 swap. Now i have a 5.0 from a 97 mercury mountaineer. Will that swap work?

I did the same swap...1997 Explorer 5.0L/2WD 4R70W transmission into my 1992 Explorer.

It has been done over 100 times, literally.

L&L motor Mounts, Torque Monster Swap Headers, Mustang (Fox) Oil Pan kit from Ford Racing, and relocating the transmission crossmember back about 2", and it is BOLTED IN....

Getting it wired up, and running.....that's a whole other story. There are 10 guys here that have done the swap, and every one of them have done it a different way. And every answer IS the right answer.

I took the easy way out, and swapped EVERYTHING over, including the dash, which required a LOT of sheet metal work...I don't recommend my method.


i ran across an ex motor in a fox with the nice cam setup on youtube yesterday. i can't remember what i typed in tho.

I'm building a 01 explorer and was wondering if the parts for a mustang would be interchangeable because the motor I'm swapping needs larger injectors and other fuel air mods that would be easily done with mustang aftermarket parts. My main concern is if the computer for the explorer would recognize for say a aftermarket maf and other mods that the computer would get readings from.

if you put in larger injectors than what came stock you most definitely will have to do a tune because the computer cannot re-adjust itself for say 24lb injectors when it came with 19lb injectors stock.

MAF sensor is a diff story. I might be wrong but from what I have been reading they don't really increase your horsepower alone they just allow your vehicle to be able to pull more air without maxing out its ability to measure the air. Performance MAF are just larger in size and have a larger operating range for measuring the air. I am looking at getting the SCT MAF just because that is who I will go with for tuning thru Henson so when I get larger injectors I can retune easily.

The Mass Air Meter needs to be matched with the Injectors. The ECM bases its calculations off the MAM signal. As long as you have enough injector for the motor, and as long as your MAM is matched for the injectors, the ECM will act accordingly. A custom tune is is always beneficial, but as long as the MAM and injectors match, it will run safe on a naturally aspirated motor. No matter what you heads, intake or stroke is. The ECC-V is very adaptable to cams also. The stock 110lph fuel pump should be adequate for any NA motor your installing.

i would recommend a tune if your changing things like that. at the moment, i have a 90mm lighting maf, 42lb injectors, and a 255 walbro fuel pump as supporting mods. it will run on a stock tune, but i am not sure about driveability (nor would i want to try).
it is tuned by james at henson performance (using a wideband and sct hand held tuner).
a lot of mustang parts can be used, some my require a little tweaking.

I was also wondering if mustang parts would bolt right up or would modifications need to be done