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Discussion Starter · #1 ·
Hello. How difficult would it be to take the engine, trans and rear end out of a 1988 Turbocoupe Thunderbird and put in in a 1991 Mustang?

Why ruin a turbocoupe for a mustang, you ask? T-Bird parts are more rare and expensive, and this needs needs work.

Will I need a new driveshaft (I have a 2.3 and 5 speed in the mustang already, but rear end is 7.5, wheara T-Bird is 8.8 I think.)

Could I just swap the ECU?

I am so excited.

And I just cant hide it.

Thanks!.
 

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Old(s) Fart
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If you are subject to emissions testing where you live, this swap will not be legal. As a general rule of thumb, you can put a newer (ie, cleaner) engine in an older car, but you cannot put an older (and thus dirtier) engine in a newer car. I don't think turbo 4 cylinders were factory available in Mustangs in 1991, so this will raise lots of red flags at the inspection station.
 

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Save a horse, Ride a Cowboy.
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I think the TB rear end is wider, wheel to wheel.

During the conversion, relocate the intercooler to the grille.

A lot of the turbo 4s got parked with engine trouble, usually overheating, and heads that are not cracked are difficult to find. In 99 we got 5 heads and never did find one crack free. Hairline cracks in the exhaust seats are common. Sometimes installing a hard seat insert will eliminate an existing crack.

The engine blocks are well made, and usually show virtually zero cylinder wear in 100,000 miles.

I know of one parked due to a minor wiring fire that the engine is believed to be ok. But parked 4 years now.
 

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aka Duke of URL
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joe_padavano said:
If you are subject to emissions testing where you live, this swap will not be legal. As a general rule of thumb, you can put a newer (ie, cleaner) engine in an older car, but you cannot put an older (and thus dirtier) engine in a newer car. I don't think turbo 4 cylinders were factory available in Mustangs in 1991, so this will raise lots of red flags at the inspection station.
Good Point! One should always check their state of residence emission law to see what they can or cannot do.
 

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Discussion Starter · #7 ·
Canada....testing free where I live!

Apparently the rear axle is and inch and a quarter wider, which should be tooo bad I would imagine (although my knowledge on the matter is minimal).

If the head is bad, I could deal with that...especially if I got the car for a steal. I just dont want to be getting in too deep.

If the tranny is in better shape, and the rear end with disc's can be swapped in, Id say that would be worth almost the price of the car itself. Iuno.
 

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Save a horse, Ride a Cowboy.
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Finding a head is a serious problem. Turbo heads are different than the non's.

Sad to say, ALL the turbo heads I have seen have been cracked. A good head will run around $ 400, IF you can find one.
 

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Discussion Starter · #9 ·
That sucks. Really stupid question here...but could the head be cracked and still operate? Not that Id drive it like that, but no point in getting one with a cracked head.
 

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BMM said:
That sucks. Really stupid question here...but could the head be cracked and still operate? Not that Id drive it like that, but no point in getting one with a cracked head.
as long as the crack dosn't go into a seat, or go into a water jacket, it might be ok, but I wouldn't even bother.
 

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A Mustang 8.8" rear would be ideal, but they can be expensive. The late-'85 through 88 T-birds used a wider rear end housing than yours, but earlier ones than mid-'85 used a Mustang-width housing with extended axles and offset brake drums. They were 7.5" units, with 3.45 gears & Traction-Lock, and I bought one from a upullit yard for $50. Swap in your axles and brake drums, and you should be good to go.
 

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A 7.5 axle might be ok with a turbo 4, since you cannot produce enough torgue to hurt it.

The turbo heads crack through the exhaust seats.

The last one I did, had minor cracking in one cyl only, and we installed a hard seat to eliminate the crack. But it took 4 heads to find it.
 

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go fast, turn left!
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the SVO mustang had the turbo 4 in it so there should be no problem dropping it in. they can still be had for a decent price. save your energy and hunt one down. It will have some value down the road.
 
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