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Restomod - 3.7 into a '66 stang fast back

Discussion in '2011-2014 V6 Mustang Tech' started by ak66stang, Jan 27, 2012.

  1. Codi_P

    Codi_P TGOD

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    $4500 could have been a built 302 and plenty of cash to spare. different isn't always better...
     
  2. falconguy

    falconguy Member

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    I put my 3.7 V6 into a 1961 Falcon and yes, I did have to fabricate new motor mounts. You should not have had to cut the tunnel. I put mine in without modifications. It was close though.

    I've done over 15 V-8 conversions into the Falcons over the years. A typical conversion with a 302 and C-4 will cross the scales at 2800+ lbs. With fuel injection one should be able to get 20-21 mpg. However, I calculate that with the V6 I'll weigh in at low 2,700 lbs and get up to 36 mpg.
     
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  3. Gareth

    Gareth New Member

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    I would really like to see pics of that 61 falcon falconguy, got any?
    Is it running and how is it working out?
    I have a 62 falcon ranchero, I am thinking of swapping a 3.7 with trans from a newer f-150 in it, and a 8.8 rearend from a late model bronco.
     
  4. falconguy

    falconguy Member

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    I have the 3.7L in my ford falcon. The stock ford motor mounts will not work. You will have to fabricate shorter mounts in order to fit between the frame rails. I used a mustang II coil over kit to eliminate the shock towers. I had to significantly modify the kit by notching it to give clearance for the oil pan. The width of the engine appears to be close to that of a 351-W conversion. I have the 6R80 6 speed automatic transmission and it fits tightly into the transmission tunnel. Tightly but fits! The stock exhaust manifolds clear quite nicely and I may end up using them. If I could be convince that a set of BBK headers would fit I would use them.

    There are about 8 different computers used on this engine. I didn't have the VIN# of the original car so I'm having to wing it on computers. I'll flash the computer if I have problems.
     
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  5. falconguy

    falconguy Member

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    I tried to post pictures as an attachment from my picture site but the site asks for my url help me and I'll get some pics out.
     
  6. Brent

    Brent Owner Staff Member

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    To post pictures you must have the pictures saved to your computer. See the screen shot below for the button to push:

    Screenshot 2013-10-22 22.32.38.png

    Once you hit the Upload a File button you can browse to where your pictures are saved and then choose them to upload.
     
  7. falconguy

    falconguy Member

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    2013-08-29 001 001 (640x480).jpg
    Needed to reduce pixels. Ok You can see that I had to open up the fender for the cold air intake. I'll get some more recent pictures.

    The facts: the falcon has the coil over mustang II kit. The stock motor mounts are far too wide for the falcon, I had to make my own mounts. The transmission is a tight fit but it fits. I trimmed some of the tabs that protruded in order to make sure there was room. The mustang II cross brace had to be cut and boxed in order to clear the pan. I cut the fender well on the other side in order to place the computer and I'll do the same for the battery. A 302 would be a much easier conversion but there is satisfaction in being one of the first. This is not a conversion for the faint of heart. A lot of things are really, really good about this engine but there is a learning curve. For example, the lower intake manifold is plastic and the heater outlet uses the quick connect fitting AND it is right in the way of the stock falcon heater outlets. I'm too timid to try the cut and weld since the intake is plastic. On the other hand Super Six Motorsports will port the lower manifold for a 55 CFM increase in flow.
     
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  8. falconguy

    falconguy Member

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    [​IMG]
    Ok, this is the passenger fender with the ecu mounted. The white lines underneath are for a battery box cut out.
     

    Attached Files:

  9. audioAl

    audioAl Coyote Red

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    Great post & project. That pony will have 315 hp on 93 octane fuel !
     
  10. Echonan

    Echonan Active Member

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    Did this build die? I have yet to see a single person anywhere on the internet who has swapped a 3.7 into ANYTHING successfully. I'm really hoping somebody somewhere has done it and can give me pointers.
     
  11. falconguy

    falconguy Member

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    I've had several conversions. Biggest was a 427 into a 1962 Falcon. Several were both carb and FI. I will tell you that the little V6 will outperform the older v8's and the frosting on the cake is that I'm getting nearly 33 mpg. For me, different has proven much better.
     
  12. falconguy

    falconguy Member

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    Your 66 Mustang has very close to the same engine compartment dimensions as my 61 Falcon. It can be done but can't with the stock shock towers. You will have to install a mustang II front suspension (not a bad idea anyway) The front cross member will have to be notched. The SR80 transmission fits quite well. You may want to trim some of the ears for additional clearance and the trans motor mount has got to be removed and a new one fabricated. If you can weld and fabricate some the motor mounts will come off of the frame and donut mounts used as in the earlier cars. I saved weight with the installation. My 62 with the small block and automatic transmission weighed 2,940 lbs. My 3.7 conversion into my 61 falcon weighs 2,840 lbs. Before I dyno tuned for maximum power I was getting +32 mpg

    Hope this helps. This is not the easiest conversion but it is the most rewarding.
     
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  13. falconguy

    falconguy Member

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    I have installed a 2012 3.7L into a 1961 Falcon. Your 1966 mustang will be nearly an identical installation. The bell housings are not the same. Unless you like shifting, throw the T-5 away and go with the 6R80 that comes with the V6. If some of the ears are cut on the transmission it fits without any modifications other than the transmission mount.
     
  14. falconguy

    falconguy Member

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    The SR80 transmission fits with minimal alteration and it is programmable . The newer mustang 3.7L..are getting better times in the 1/4 plus better mileage.
     
  15. falconguy

    falconguy Member

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    The only thing you will need to address is to bypass the PATS (Passive Automotive Theft System) You may be able to send the ECU out or just obtain the transponder key and coil and wire those in. I was going to do that which I could have hidden for a good theft deterrent but there simply wasn't enough room.
    Go to my garage for the pictures.
     
  16. falconguy

    falconguy Member

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    The 3.7L will fit but the stock mustang shock towers will have to be eliminated and an aftermarket MustangII put in. The mustang II will, or should have, a notch in the cross brace to clear the oil pan. There should be slightly more room in the mustang than in the falcon. IMG_1424.JPG
    IMG_1424.JPG
     
  17. falconguy

    falconguy Member

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    I've osted at picture and yes it is running. The conversion exceeded my expectations. It is a very tight fit. The mustang II must be installed and there must be a notch in the crossmember to clear. You will have to fabricate your own motor mounts. You will need a returnless fuel system. Aeromotive makes an in-tank fuel pump that works well . Keep the wiring from the F-150. You will need the fuel pump modulator, smart junction box, battery junction box and ecu to complete the change. The ecu will have to be flashed to eliminate the auto theft system. Call Art at wire diet and he can fill you in on the electrical needs.
     
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  18. falconguy

    falconguy Member

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    I have a 2012 3.7L V6 installed in my 1961 Falcon. If it fits in the Falcon, it'll fit in the Mustang. You will have to disable the PATS and you will need the battery junction box and smart junction box. Use the electrical throttle control from the donor car...fits right in and no linkage to mess around with. I'm surprised you have transmission tunnel problems! Mine fit right in but I had to remove the small ears cast into the transmission. The stock falcon transmission cross member and supporting brace had to be removed. I initially had problems with the SR80 shifting but later learned at the dyno shop that this transmission can be programmed and that it "learns" how you drive. After dyno tuning the engine produces ~327 flywheel hp. This is at > 4,000ft. elevation. On two initial tests through the mountains I averaged 32.4 MPG and on a third test in flatter land it got over 35 mpg. In all, the Falcon weighs a couple of pounds over 2,800 lbs.

    You can expect similar results with your early mustang.