91 mustang lx

Discussion in '2.3L (N/A & Turbo) Tech' started by XxFaceYourFear, Aug 27, 2011.


  1. XxFaceYourFear

    XxFaceYourFear New Member

    Joined:
    Jun 9, 2007
    Messages:
    37
    Likes Received:
    0
    Trophy Points:
    0
    Hello all, I have a 1991 notch that has a bad power steering pump, an engine oil leak somewhere, a bad ac condenser and a few other odds and ends I plan on fixing here pretty soon. A friend of mine has a drive train out of a 87-90 fox in a model t project that he's stripping out for a 350. I'm planning on buying it from him, replacing gaskets/whatever needs replacing then swapping on the 8 spark plug head from my engine onto this one then putting it back in my car. Are there any problems I will be encountering or any reason why I shouldn't do this? I'm assuming the pistons/all other internals are identical, am I correct?

    Thanks in advance!
    #1
  2. bonestock87

    bonestock87 Founding Member

    Joined:
    Dec 19, 2001
    Messages:
    733
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    East TN
    So you're just swapping out the shortblock? The only issue I see with this is the 87-90 block doesn't have the provision down at the crank pulley for the crankshaft position sensor due to the DIS ignition system used on the dual plug engines. The 87-90 block can be made to work with your 91 wiring but you'll have to drill 2 small holes to mount that sensor.
    #2
  3. XxFaceYourFear

    XxFaceYourFear New Member

    Joined:
    Jun 9, 2007
    Messages:
    37
    Likes Received:
    0
    Trophy Points:
    0
    Haha, I guess it would have been easier to say I was going to swap the shortblocks. When I drill the holes, am I going to need to thread these with a tap and die set as well, or does the sensor mount through these holes?
    #3
  4. bonestock87

    bonestock87 Founding Member

    Joined:
    Dec 19, 2001
    Messages:
    733
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    East TN
    Drill and tap. I would take the timing cover off of your 91 and down at the crank pulley you'll see that sensor. It has two pretty small bolts that hold it on. The wires feeding it go behind the back of the timing cover and up to the harness.
    #4
  5. XxFaceYourFear

    XxFaceYourFear New Member

    Joined:
    Jun 9, 2007
    Messages:
    37
    Likes Received:
    0
    Trophy Points:
    0
    Cool, I will definitely be doing that. I may have a 2.3 from a 96 ranger available as well, so whichever is in better condition will be used for the swap. Also, I'm planning to do a 3G alternator swap and wanted to know which were compatible parts. My searching points to a 94-95 5.0 alternator, would a 94-98 3.8 alternator swap in the same?
    #5
  6. Delray Dude

    Delray Dude New Member

    Joined:
    Jul 7, 2010
    Messages:
    263
    Likes Received:
    0
    Trophy Points:
    0
    Yes - any 94 to 99 Mustang alternator will be the 130 amp 3G. However, there are 100 amp versions of the 3G and they are easy to recognize in the yard.


    The 130 amp versions and the 100 all have small holes drilled into the front face for breathing. Pay attention to the front face and look at it. There are three "spokes" for lack of better terms extending out from the center. A 130 amp version will have two big holes in each of the spokes, one closer to the center and the other closer to the outside edge.
    The 100 amp version will have 4 smaller holes in each spoke - 2 side by side and the other 2 side by side.

    Below is a link that shows the differences, look at the front view pictures below the side ones, the one on the left is the case style you are looking for - pic shows the wrong mounting - but the front case holes is what you are looking for

    3G Series Heavy Duty Bridge Rectifier High Output Alternator


    Also, any 96 to 99 3.8 Thunderbird or Cougar will have the correct 130 amp 3G alternator. The V-8 will have a 3G as well, but the mounting will not work for you.

    Also certain front wheel drive mid 90's contours or taurus types have the correct alternator too.

    Be aware there are some out there with 8" on center mounting holes - the top ear extends out more, you are looking for the 7" on center mounting holes
    #6
  7. XxFaceYourFear

    XxFaceYourFear New Member

    Joined:
    Jun 9, 2007
    Messages:
    37
    Likes Received:
    0
    Trophy Points:
    0
    Well (although it is pretty late) thank you for your guys' input. I'm going to be going in a different direction with the car now. I came across a 1991 gt that was wrecked for 300 bucks, so I bought it and will be performing a 5.0 swap on my coupe. It also has a couple of nice usable pieces on the inside that I will be transferring over to mine. Once the swap is done, I'll probably put the 4 banger stuff in the wrecked car and take it to a junkyard. Most places around here pay out 300 bucks per car.
    #7

Share This Page