Ext Cab to Crew Conversion Question

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1996greanbean

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Well it seems odd I’ve been going to this website for the last 5 years for advice and never once registered so I’m brand new here. I’m sure one of you knows the answer to my probable obvious question but I have to ask because I haven’t seen any other discussions about it.

Little background. I have a 1996 Chevy k1500 3 door with manual 4x4 floor shift, 4l60e, 4 plug ecm. I recently purchased a cab from a 1997 K3500. My original plan was to swap the crew cab onto my ext cab frame (yes I’m aware they don’t bolt right up, I’m not worried about the amount of fabrication required) and take all of my wiring from inside the cab of my 96 and swap it into the crew cab so I would retain the fuse box and other electrical hookups from the 96. As I was tearing down the cab electronics from the outside of the 97 k3500 crew cab I realized they appeared to have the same plug for ecm on the drivers side. My question is could I just use the existing electronics inside of the 97 and not swap in my 96 wiring, fuse box, etc… it would save a ton of time and I wouldn’t need to run extra wire from the fuse box for the rear window motors and extra above head cab lights. Also the 97k3500 was a 6.5 truck. I’m just not sure if all the internal wiring of the cab is not related to the motor/trans. Any help would be appreciated and I apologize if it’s an obvious answer. Thanks!
 

evilunclegrimace

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Well it seems odd I’ve been going to this website for the last 5 years for advice and never once registered so I’m brand new here. I’m sure one of you knows the answer to my probable obvious question but I have to ask because I haven’t seen any other discussions about it.

Little background. I have a 1996 Chevy k1500 3 door with manual 4x4 floor shift, 4l60e, 4 plug ecm. I recently purchased a cab from a 1997 K3500. My original plan was to swap the crew cab onto my ext cab frame (yes I’m aware they don’t bolt right up, I’m not worried about the amount of fabrication required) and take all of my wiring from inside the cab of my 96 and swap it into the crew cab so I would retain the fuse box and other electrical hookups from the 96. As I was tearing down the cab electronics from the outside of the 97 k3500 crew cab I realized they appeared to have the same plug for ecm on the drivers side. My question is could I just use the existing electronics inside of the 97 and not swap in my 96 wiring, fuse box, etc… it would save a ton of time and I wouldn’t need to run extra wire from the fuse box for the rear window motors and extra above head cab lights. Also the 97k3500 was a 6.5 truck. I’m just not sure if all the internal wiring of the cab is not related to the motor/trans. Any help would be appreciated and I apologize if it’s an obvious answer. Thanks!
Are you sure that the truck is a '96? The reason I ask is I have only seen 5 plug ECM's on '96 and '97 trucks.I was under the impression that the 4 plug ECM started in '98. If I am mistaken someone will correct me .
 

1996greanbean

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Are you sure that the truck is a '96? The reason I ask is I have only seen 5 plug ECM's on '96 and '97 trucks.I was under the impression that the 4 plug ECM started in '98. If I am mistaken someone will correct me .
Sorry you are correct, I swapped a motor out of a 98 Tahoe into it about 2 years ago and had to change a few accessories to hookup with the 96 harness. It is a 5 plug. My brain was a little scrambled when I made the post early this morning.
 

movietvet

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Welcome to the forum from Oregon.

How will you address the box at the back?
 

1996greanbean

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Welcome to the forum. I was in your area of Alabama just a few weeks ago.

If you need measurements or mount info, I’ve got a bare crew cab k3500 frame that I can get them from.

Good luck with your project.
Thanks for the offer, I’m afraid I still have quite a few parts to source before I start worrying about actually cutting and mocking up the mounts. I still need custom length driveshaft, fuel hose, brake line extensions, tail lights extensions, and another 1500 frame I can cut about 13in out of. So I imagine I’ll be into this for a couple months before it’s finished.
 

1996greanbean

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what are you going to do about the bed
Planning on cutting frame and adding about 13 inches behind driver door (where frame is still straight) and then building custom cab mounts. Plan on leaving everything behind the cab the same. I don’t want to deal with having to change leaf spring hanger setups and making it over complicated.
 
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