140 speedo swap into 88gt

jz88vert

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Jun 12, 2022
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I have an 88 GT convertible and I got a dash cluster from my buddies 93 GT I've heard many different things on here about doing the swap I'm trying to see if I pull the speedo out of his 93 and take the mechanism off the back do I need to remove the stop pin and let the needle fall down and swap it and then pick it back up and put the pin in and use the Whiteface 140 gauges if this will work properly for the calibration if anyone can let me know I would appreciate it. I dont really want to use his whole speedo and drill holes and file and cut stuff
 

Mustang5L5

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Feb 18, 2001
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I have an 88 GT convertible and I got a dash cluster from my buddies 93 GT I've heard many different things on here about doing the swap I'm trying to see if I pull the speedo out of his 93 and take the mechanism off the back do I need to remove the stop pin and let the needle fall down and swap it and then pick it back up and put the pin in and use the Whiteface 140 gauges if this will work properly for the calibration if anyone can let me know I would appreciate it. I dont really want to use his whole speedo and drill holes and file and cut stuff


Won't work.

You are better off selling the 90-93 cluster on Ebay for $150-200 and using the funds to buy something like this.



That will bolt right into an 87-89 cluster without any modifications.


If you try to put a 90-93 speedo into a 87-89 cluster, you'll find the bottom of the speedometer is a different shape and don't really fit into the cluster cleanly. There will be a gap at the bottom. You can attempt to disassemble the 87-89 speedometer and the 90-93 speedometer and swap the guts and speedo face over, but i've found once you peel those guage faces off, they never stick right again and look like junk at night. The guage face doesn't fully cover the plastic clear frame either, so there will be a large gap at the bottom.

For the work involved to give a less than perfect result, just sell the cluster and buy the right unit
 
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jz88vert

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Jun 12, 2022
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I just confirmed with my buddy the 140 cluster he gave me out of his 93 GT was originally black and he just put white face overlays on it. I was planning on gutting it but didnt no whether to take whole speedo plate out and drill holes and trim it to fit or remove speedo mechanism and swap it with my 85 and just use my white face overlays on my teach voltage gas and temp. Why were u saying this wont work. From all research ive done i thought it would just wasnt sure about removing stop pin and resetting it or how to do it. I read alot of ur replies on other threads and sounds like u really know alot about foxbodys so I was glad u were the one who replied. I already have everything and wasnt thing to go thru the hassle of selling one he gave and finding another and all that BS. I was surre there was someway it would work I know the 93 whole cluster wont bolt up cuz of the arch for airbag and heard if u plug it in 88gt there would be problems cuz of some wiring. Its all just confusing reading many different threads and peoples reponses are all different. I appreciate your response but let me know why it wont work or is there anything I can do to make it. I have new white face overlays on package from lmr and the led upgrade I wasnjust waiting to do it all at once
 

Mustang5L5

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Do you have brand spanking new gauge face overlays?


If so, then it’s easier. Most folks want to retain the stock faces which makes this tricky.


Pull the needle off. Flip the speedo over and undo the two small bolts and remove the entire speedo mechanism. All you need is this

6936E33D-CC5D-490A-8500-9F0DB1EFD231.jpeg


Do a full swap with your old 85 mph speedo head. Swap on your new faces, and align your needle like i mentioned in the other post.

The two bolts that hold it to the plastic frame are at the 3 and 9 o’clock position.

F979887C-9F80-489E-B198-D566ED4DA19B.jpeg
 
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Mustang5L5

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Here’s the main reason why swapping the 90-93 speedo over to the 87-89 doesn’t work unless you have brand new faces. The bottom is shaped differently.

87-89 on left, 90-93 on right

A829D5BE-4D0C-41E3-9336-68DB7B0D248A.jpeg
 

jz88vert

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Jun 12, 2022
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Ok makes more sense now. Yes brand new pack of white face overlays. Removing the needle and getting it back on correctly was what I was worried about. My buddy already out whites faces on it so I didnt wanna try n cover it twice or try n peel his overlay off and mess something up. I heard getting the needle off is a little trick to but to use a fork. Heres overlays I have since im only using 93 speedo mechanism not the whole speedo which 140 overlay and rpm do i use. The 92-93 speedo or the 90-91. And which rpm the 93, 90-93, 92-93, or the 90-91. I appreciate all ur help sorting this out. And that's my cluster that's currently in my car
 

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Mustang5L5

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One more thing so the 140 new whites will cover my stock 85mph and lines will all match up?

Now that I see these faces, I’m not sure it will work the way you want. They appear to overlay the stock guages and allow the light to shine through. All the differences in the faces are for the different font changes thru 90-93. You can see how the numbers change size and some of the tick marks move slightly.

The correct oil pressure/fuel guage for 87-89 is the one with 0 and 100psi. You’ll have to match up the coolant and volts as the tick marks on the coolant are in different spots.

For the tach, the 6k one is for a 4cyl. You’ll have to pick the best match for 87-89 but it will block the check engine light and low oil light.

As for the speedo, it won’t work over the 85mph face. I doubt it will light up at night.
 

jz88vert

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Jun 12, 2022
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Thanks for all ur help. Finally know now it wont work. I found the one with the flat bottom not the arch for airbag local going to see it tomorrow. Ad said fits 97-93 so dont think he knows the differences. But as long as its the flat bottom it will bolt right in but my question is will the plugs plug right in and evrything work without having to mess with any wiring? This is only oic he had posted but did 90 have flat bottom and if so is wiring plugs in 90 still same as 88
 

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Mustang5L5

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Those are 90-93 faces. None are ideal. You'll just have to pick the best ones that match up.

If you can get the correct 87-89 faces i would go that route.
 
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jz88vert

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Jun 12, 2022
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Well scratch all that I just went and met the guy and when he brought it outside it wasnt one from pic he posted it was a 90-93 with the arch insaid inalready have one of those with white faces it wont wont so im back to square one.
 

jz88vert

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Jun 12, 2022
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Injust seen a thread from Xtant said he made it work by trimming 90s speedo drilled some holes and grinder the nubbies off and had small gap. I can live with small gap if it doesnt look like craps. Will this work though and will those whitefaces I posted before work with this way. Clusters are going thru the roof is seen somebfor 300 and up even one for 500. For all that might as well spend more and do the dakota digital
 

Mustang5L5

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No idea those particular white faces will work or how to make them work. I'm not a fan of them. Every set I have messes with looked terrible at night.

You don't need an entire cluster. You can just add this to your 87-89 cluster with the 85MPH speedo. If you have the 90-93 cluster, just sell that for $150-200 and you are done. You can even match the mileage. Swapping in the speedo is easy.


or




I would personally buy the Motorsport one as that's a good price for that one. I might snag it myself
 

jz88vert

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Jun 12, 2022
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I was trying to be cheap. But F it i just bought the one. I seen the other one u sent to it said it was making a scratching noise and might need rebuilt so I didnt wanna pay that amount and have it be messed up. But thanks for all your input on everything it was very helpful or I woulda totally messed some stuff up and been pissed
 
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