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2.5 to 2.8 complete cradle swap by snyderman
Started on: 10-06-2014 08:36 PM
Replies: 7 (354 views)
Last post by: mckaymotoworks on 12-04-2014 10:17 AM
snyderman
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Report this Post10-06-2014 08:36 PM Click Here to See the Profile for snydermanSend a Private Message to snydermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
I apologize if I overlooked a previous thread on this subject. If someone knows one that exists please point me to it.

I have an '84 duke I'd like to upgrade to a 2.8. I'm only semi mechanically inclined so I thought it would probably be best that I buy a donor GT with a standard tranny and 2.8 and drop the complete cradle and simply swap them. Is this the easiest approach?

Thanks in advance.
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Report this Post10-06-2014 08:50 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
Unfortunately, the 84 has unique wiring and the main connections in the engine bay are in a bad location for the V6. The V6 wasn't offered until 85 and the chassis side of the wiring harness was changed to accommodate it. The cleanest way to swap in a V6 into a 84 will likely require swapping over to the 85+ chassis harness. So if you have a whole parts car, plan on swapping the chassis harness as well... which is a fair amount of work.

On anything but an 84, the 2.5 to 2.8 V6 is a pretty simple swap.
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snyderman
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Report this Post10-06-2014 10:19 PM Click Here to See the Profile for snydermanSend a Private Message to snydermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks Fieroguru

So if I understand correctly, I can't just expect to move the C500 from the firewall to the battery area and connect the wires to the '84 chassis harness. What is involved with changing the chassis harness? Is the harness everything under the dash, ecm and headlights etc. or is it just on part of it?
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theogre
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Report this Post10-07-2014 12:41 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
84 C500 plastic is not same as Later C500.

quick example the alternator output wire goes thru 84 C500. the circuit uses a big terminal too.
See my Cave, Alternator Sense

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snyderman
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Report this Post10-09-2014 12:33 AM Click Here to See the Profile for snydermanSend a Private Message to snydermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks Orge, but looks a little complicated for this old brain of mine. Anyone out there capable of splicing me together a v6 engine harness to fit an '84 body harness? Looking for a plug and play option. If it requires upgrading the ecm to a 7300, that would be even better.
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TopNotch
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Report this Post10-09-2014 08:51 AM Click Here to See the Profile for TopNotchClick Here to visit TopNotch's HomePageSend a Private Message to TopNotchEdit/Delete MessageReply w/QuoteDirect Link to This Post
Here is an article about how to put a V6 in an 84.
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snyderman
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Report this Post10-09-2014 09:07 AM Click Here to See the Profile for snydermanSend a Private Message to snydermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thank you
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mckaymotoworks
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Report this Post12-04-2014 10:17 AM Click Here to See the Profile for mckaymotoworksClick Here to visit mckaymotoworks's HomePageSend a Private Message to mckaymotoworksEdit/Delete MessageReply w/QuoteDirect Link to This Post
I've read through Ted Hamm's guide, seems the easiest way to accomplish this swap would be to have the entire V6 harness to replace the 84' along with the other item's on his list. I am in a state of flux on which swap to undertake, this appeals the most since it would be drop and drive provided you have all the necessary components on hand.

On one hand, I would love the 3800SC, but being the perfectionist I am, I do not have the shop space or tools to execute it at this time as clean as I would want.
The thought of having an otherwise stock appearing 84' with the later V6 cleanly installed aligns with my past car projects of reinterpreting what the engineers could or should have done. I have never been keen on completely making a car something it was never intended to be.

So with that, if I read through the guide and the other 84/2.8 threads, the best way is to have all the harnesses from the V6 along with engine, transmission, cradle, A/C components, ECU, V6 radiator. Basically drop the 2.5, strip the interior, dash, rewire with V6 harnesses, make the cooling tube and fuel line modifications and you would have pretty much a factory install of a 2.8 in an 84' chassis?
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