Which harness/ECU do I look for?
Which harness/ECU do I look for? Ok, so I've tried searching Google, but just haven't found the answers...I'm doing a fox swap with a 99-02 5.3(I'm not sure what year it is nor do I know how to tell yet). It will have a LS6 cam/spring upgrade and Pro Products 85mm intake. The fuel injectors I intend to use are FRPP's that I have left over from various mustang builds. I only have 4 of 8 truck coils, so I will either need to purchase a new set of 8, or at least purchase 4 to match the ones I have. The transmission will be a 4l60(non-electronic). So which harness/ECU combo should I be looking for? LS1 or 5.3L? Manual ECU since I am running non-electronic trans? Thanks ahead for helping a LS/Chevy noob.
Teching In
Joined: Feb 2015
Posts: 19
Likes: 0
From: Beaumont, TX
Ok, so I've tried searching Google, but just haven't found the answers...I'm doing a fox swap with a 99-02 5.3(I'm not sure what year it is nor do I know how to tell yet). It will have a LS6 cam/spring upgrade and Pro Products 85mm intake. The fuel injectors I intend to use are FRPP's that I have left over from various mustang builds. I only have 4 of 8 truck coils, so I will either need to purchase a new set of 8, or at least purchase 4 to match the ones I have. The transmission will be a 4l60(non-electronic). So which harness/ECU combo should I be looking for? LS1 or 5.3L? Manual ECU since I am running non-electronic trans? Thanks ahead for helping a LS/Chevy noob.
TECH Enthusiast
Joined: Sep 2014
Posts: 732
Likes: 1
From: alburnett, iowa
not sure but I believe trucks have 2 different style coils. connectors too different from car version? I know truck & car differ on injectors & plug connectors. get your intake & fuel figured before wiring it.
On The Tree
Joined: Jul 2014
Posts: 143
Likes: 0
From: Lincoln, CA
Pretty sure the OP has moved on since this thread was started a year and a half ago lol.
If it were me and I needed a harness with minimal connections, I'd hit up one of our sponsors like PSI or BP Automotive that specialize in making stand alone harnesses. Used harnesses can go for $150-350+ depending on the condition and who's selling it and then you still have to spend a pretty significant amount of time cleaning it up and removing all of the un-needed wiring. Or you can pay a little more ($500+ depending on the harness) and get a brand new one made specific to your engine.
If you want to find a used harness pretty much any 99-02 truck/SUV harness will work since all of the 4.8/5.3/6.0 engines basically had all of the same connections in the same places. It's not all that hard to modify your own harness if you want, just be prepared to spend a full day or two on it if it's your first one. You can check out lt1swap for tons of really good info, excellent step-by-step instructions, and a very reasonable pcm reflash service.
If it were me and I needed a harness with minimal connections, I'd hit up one of our sponsors like PSI or BP Automotive that specialize in making stand alone harnesses. Used harnesses can go for $150-350+ depending on the condition and who's selling it and then you still have to spend a pretty significant amount of time cleaning it up and removing all of the un-needed wiring. Or you can pay a little more ($500+ depending on the harness) and get a brand new one made specific to your engine.
If you want to find a used harness pretty much any 99-02 truck/SUV harness will work since all of the 4.8/5.3/6.0 engines basically had all of the same connections in the same places. It's not all that hard to modify your own harness if you want, just be prepared to spend a full day or two on it if it's your first one. You can check out lt1swap for tons of really good info, excellent step-by-step instructions, and a very reasonable pcm reflash service.
