86 Duke to 84 Duke swap (Page 1/1)
weatherstud AUG 29, 08:25 AM
Quick question.

First off, yes, I know that what I am doing flies in the face of what one would usually do when swapping engines. However, I just want to actually drive my Fiero and not dump additional gawd-awful money into by jumping to the 3800 or 4.9 arenas. My work pays mileage at the same rate if I get 10mpg or 30....so I might as well go with what I have and what can be done quick.

I have 86 base coupe. The original 185k mile iron duke grenaded and locked up.

I have low mile 1984 iron duke sitting in my shop with the complete holley set up that I am just going to put right in.

It should be mostly plug and play, right?...Except it seems I may need to keep the 86 distributor (new cap and rotor of course) due to wring hook ups, and then swapping out the 86 throttle cable for an 84 throttle cable. I wont have to do anything with the ECM, will I?

Anything else I need to pay attention to in an later duke to early duke swap?
cartercarbaficionado AUG 30, 04:09 AM

quote
Originally posted by weatherstud:

Quick question.

First off, yes, I know that what I am doing flies in the face of what one would usually do when swapping engines. However, I just want to actually drive my Fiero and not dump additional gawd-awful money into by jumping to the 3800 or 4.9 arenas. My work pays mileage at the same rate if I get 10mpg or 30....so I might as well go with what I have and what can be done quick.

I have 86 base coupe. The original 185k mile iron duke grenaded and locked up.

I have low mile 1984 iron duke sitting in my shop with the complete holley set up that I am just going to put right in.

It should be mostly plug and play, right?...Except it seems I may need to keep the 86 distributor (new cap and rotor of course) due to wring hook ups, and then swapping out the 86 throttle cable for an 84 throttle cable. I wont have to do anything with the ECM, will I?

Anything else I need to pay attention to in an later duke to early duke swap?


I have experience swapping a later duke I to an early one. yeah no ecm is the same and engines are basically the same but you need to swap the entire intake for some years if your using the stock fuel injection. pretty much just change the important stuff (water pump,ac and alternator should all be the same) and it's just gonna be ignition and fuel system related things really. 87 and up is the hard ones
Dennis LaGrua AUG 30, 09:34 AM
Swapping the later Duke engines to an earlier vehicle that didn't have DIS sounds very similar to what we have done on the 2.8L-3.4L swap. The longblock is used while all the bolt on parts are transferred. The good part is that the 3.4L has the cam gear for the 2.8L distributor. If the later Duke engines have the distributor hole and cam gear then the swap job should go well.

------------------
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82-T/A [At Work] AUG 30, 10:48 PM
The ONLY real difference between the 1984 Iron Duke, and the 1986 Iron Duke, is that the 1986 has a roller cam. Everything else is basically the same.


You want to make sure that you use everything from the 1986 on your 1984. Of course, you can keep the intake and the Holley TBI unit... as both of those are direct replacements. Some of the differences though is that the 1984 had a slightly different distributor and a slightly different ignition coil connector. So again, you want to use ALL of that from the 1986.

Another key thing is that the 1986 Iron Duke has a V5 compressor, which is a highly sought-after improvement over the 84-85 Fiero. So make sure you keep the 1986 compressor when you swap in the 1984 motor.


The blocks are basically identical except for the provisions for the roller cam. Everything else will bolt up the same.