Engine Will it fit/work

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Randy1985

Member
Jul 10, 2022
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Cochran ga
Is the door sticker still on the car?

Bottom right corner under “TR”. What letters/numbers are there.

You can also just pull the air cleaner lid and look for the two fuel injectors sitting in the "carb"

1657717321921.png
It has a street demon carb on it now
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
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It has a street demon carb on it now
MOST complained about carb EVER..... I have read many articles about it being hard to tune and MOST people NOT KNOWING how to tune it, so I can't say its a bad carb, just a "misunderstood" one....
My friend and his father bought a bunch of stock in the Demon company when this carb came out..... I don't think they lost any money, but they certainly did not make the killing they thought they were......
 
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Gs1987GT

Active Member
Sep 25, 2019
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It was H.O.

The 85 H.O. CFI engine had a roller block but still used the flat tappet cam/lifter from 82-84. It also had the exhaust system from model year 84, until mid Nov 84 when it got the 85 4V exhaust. The exhaust switch got a 15 HP bump. See the chart above.
Very interesting and is what I remembered, but wasn't sure if my memory was failing me or not. Thanks for the clarification. It explains why it was down on power compared to its roller cam cousins. I did not know it was the same block though. Was there any modifications necessary to put the roller cam in that block beyond the physical components?

We pulled the cfi off of my brother's 85 GT back in the day and went to a Holley care and an edelbrock aluminum intake manifold. Even with the flat tapper cam the car ran real well. It was no slouch. Definitely ran better with the carb than with the cfi.

The car was originally an AOD, we converted to 5 speed which also helped in the performance department.
 

FoxChasis

10 Year Member
Dec 23, 2003
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Very interesting and is what I remembered, but wasn't sure if my memory was failing me or not. Thanks for the clarification. It explains why it was down on power compared to its roller cam cousins. I did not know it was the same block though. Was there any modifications necessary to put the roller cam in that block beyond the physical components?
Sometimes the holes in the oil return valley for the lifter connector hold-down bracket were threaded, sometimes they were not. If they were not threaded they would need to tapped for the bolt thread. Otherwise I believe it's a straight drop-in for the roller components. And don't forget the driven gear on the distributor needs to be changed also, to be compatible with the steel drive gear on the cam.
 
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Gs1987GT

Active Member
Sep 25, 2019
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Sometimes the holes in the oil return valley for the lifter connector hold-down bracket were threaded, sometimes they were not. If they were not threaded they would need to tapped for the bolt thread. Otherwise I believe it's a straight drop-in for the roller components. And don't forget the driven gear on the distributor needs to be changed also, to be compatible with the steel drive gear on the cam.
Good info, thanks.
 

Willybill32

But at least it's tight!
Jul 16, 2019
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Lexington, KY
Mustang GT's never got CFI like the Lincolns and T Birds
His 85 had a Holley 600 on it from the factory
The Mustangs went from the HO Holleys straight to multiport fuel injection in 86 or 87
Randy 1985, I think you should find a close to factory Holley 600 with the rear screws
Install it with some steel needles
Stock they run a bit faster than the fuelies
Stock they are worth more money
SEFI was added to the 5.0 in 1986.

Bill
 

Ranger

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Jun 10, 2013
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MOST complained about carb EVER..... I have read many articles about it being hard to tune and MOST people NOT KNOWING how to tune it, so I can't say its a bad carb, just a "misunderstood" one....
My friend and his father bought a bunch of stock in the Demon company when this carb came out..... I don't think they lost any money, but they certainly did not make the killing they thought they were......
many times more carb than the car required ... I remember the Holley 3310 double pumper was being installed on even 289 c codes back in the day and guys whining about it bogging down ... they just liked having a double pumper 'cause it was cool
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
3,094
1,799
143
67
Florida
many times more carb than the car required ... I remember the Holley 3310 double pumper was being installed on even 289 c codes back in the day and guys whining about it bogging down ... they just liked having a double pumper 'cause it was cool
Over carbed and over cammed cars do poorly on the street for decent drivers.... WAY before the internet all we had was Hot Rod magazine to guide us..... LOL...
 

limp

wrap a little cheese around it and its a done
Oct 4, 2020
3,094
1,799
143
67
Florida
I remember so many over carbureted cars from my youth I am going to try something different..
No race car, just a grocery getter... 030 over Explorer engine, "P" heads, TF Stage 1 cam, forged pistons with a goal of 9-1.... shorty headers with the stock aluminum intake that came on the car.......
I purchased the 500 CFM carb in the pic to try out and see what happens......
If I ever get to putting it together and NOT taking more of it apart, I will let everyone on here know.....
DSCF1070.JPG
 

manicmechanic007

5 Year Member
Sep 26, 2017
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Those are pretty good carbs in my opinion
A friend has one on a 76 El Camino
I had to fix it only once in about 10 years
I remember the repair being minor but we had to get the kit from Summit
You'll love it
 
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