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Unconventional Builder
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I am looking into an 88 GT currently in a back yard rusting. It’s supposed to have new clutch, f-cam (?) and 4.11 rear. The car still has what is needed. The interior, seats carpet trim panels hatch back etc, have been parted out. The drive train, suspension steering and brakes remain. It is able to start. I have read Peal’s posts and I am still not clear on the 88 to 89 motor changes.

Is there anything to this year car that would make it more challenging like the 94 – 03’s. I have learned that good compatible donors are 1989-1992’s. What I don’t understand is the speed density cars, vs Mass Air cars (87& 88’s vs 89-92’s)?? I am planning on tearing down and rebuilding it , motor, tranny rear, for the next 2 years perhaps some auto cross then do the transplant to a MKIII with all optional control arms, coil-overs etc.
 

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i got my 88gt donor and rebuilt motor and rear. im going carb. the stuff was all rusted so i didnt wana use the speed denisty. but it would work. just make sure the parts are not to rusty. i got mine for 800 and it was runing... granted the clutch was about out.
 

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It's a car!
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I factory ordered my '88 GT donor new and drove it to its retirement as a pure stock speed density. It always had a power surge at about 1800 RPM that felt like an old tri-power kicking in, but that could just as likely have been 'coming on the cam' as fuel delivery.

The 88 is bullet proof, and I'll be using mine as is for my build. However, I'm told if you plan to re-cam, supercharge, etc, the speed density gets hopelessly confused so you'll have to convert to mass flow.

A lot of the guys here have made the conversion and I'm sure they'll add more info. Meanwhile, I'd say if the price is right, and you realize donor clean-up is very labor intensive, go for it - Bruce
 

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FFCobra Fanatic
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The major donor parts you'll use will be fine. Having speed density is the biggest difference.
If your plan is to go carb'ed this has no effect. Other options are convert to mass flow either mustang or after market if wanting efi but not SD set up. Depending on your build this year also has the fox width rear that is a little narrower compared to the newer models. allows the largest rear tire if going solid axle.
 

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History:

All 87 Mustangs with a 302 were controlled via a "Speed Density" computer strategy. In 1988, all California-spec Mustangs with a 302 were controlled by a "Mass Air" computer strategy; all other 1988 302's were still Speed Density. In 1989, all Mustang 302's were converted to the "Mass Air" strategy.

What this means to you:

A Speed Density controlled engine does not react well to performance upgrades like heads, intake, cam, etc. If you have a Speed Density controlled engine, you will likely want to convert it to Mass Air buy purchasing a Mass-Air computer, a Mass Air Sensor, and a few wiring harness bits. These kits are readily available from FRPP and Summit, to name a few.

As Hind Sight mentioned, throw all this out the window if you are going to convert to a carb system; the computer and associated air metering bits go in the trash.

Hope this clarifies,

Greg
 

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One more thing:

The 1992 and 1993 Mustang 302s were essentially the same, but the largest change occured in 1993 when they changed the pistons from forged to hypereutectic. The forged pistons were much stronger and better suited to forced induction power adders like blowers, so that's why you hear guys tell you the "best" years (if going with a Fox donor) are 89-92.

-Greg
 
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