I'm picking up a 5.3L L33 tomorrow. I am planning on running a LS1 intake, DBC throttle body, and a T56 transmission.

What is the preferred wiring harness and ECU to use with this setup?

 

stock

 

I think the easiest would be a F-body w/ a 6 speed harness.

 

I ended up returning the 5.3L block due to a crack that I found, and now I have a 2000 LS1 from a F-body.

I've been watching for a 2000 (1999-2002) wiring harness from a F-body w/T56 and these harnesses seem to go quickly. I haven't been fast enough to get one.

I plan on shopping for the "correct" harness, but if I can't find it, what are the next easiest harnesses to adapt in order of simplicity?

1999-2002 F-body/automatic harness
1998 F-body harnesses
????

 

1999-2002 Truck intake would be easy to adapt, just some small differences. Injectors connectors are different between truck and LS motors. The transmission wiring would be different all together, you will have to do some cutting and splicing, but the price is usually right on those harnesses. You can get the T56 connectors from a few places, just take some time and took over some diagrams, you can figure it out and adapt accordingly.

 

If using the earlier truck harness, is it still preferred to use the Camaro ECM, or will the truck ECM be just as adaptable?

 

speartech has standalone harnesses or can rework a factory harness

 

yeah, I've got them down as an option. I'd like to give it a shot at figuring it out first, though. I know I can just jump in and do it, but I'd like to avoid any costly purchase mistakes if possible. Ie, I don't want to buy the truck harness, if I'm going to have spend more on extra connectors/wire to make it work.

Basically trying to figure out if there are any pitfalls that someone else has already found.

 

U can usually find the harness on eBay alot.. even some converted to stand alone ones.. I'd check the forum on any of the ones you are interested in. To see if any have used these harness by either a User or Company.

Painless is another option, as is some of the sponsors on this forum. check Currentperformance, they are one. Wait4meperformance (u already check S&P). You got a few to check with.

 

I think it depends on the year of truck PCM, but Wait4me changed my 2002 truck PCM to a Camaro tune (Ls1) and it works great.

 

The 99-02 f-body and the 99-02 trucks use the same physical PCM, it is just the programming that differs. So the PCM can be used for either application if you flash it accordingly.

 

This makes sense, but from what I read in one of your other posts, there are some pinout differences in the PCM. The one I am specifically concerned about is the coolant temp sensor ground on pin 63. Do the wires actually need to be changed in the harness?

Thanks
Ken

 

I would just move the wires to match the computer as its very easy to do. I suspect that both PCM`s have multiple pins that are tied together internally and all go back to the same ground, but I do not have any evidence to confirm that.