Helping a friend swap an LQ4 into his 02 Z71. He has a complete LQ4/80e drop out with harness and ecu from an 02 truck as well. He also has a Speartech 80e swap conversion harness thing. Every swap I have found here has used the stock 5.3 harness and ecu and then done a segment swap or used the Speartech adapter. Is it not possible to use the stock harness and ecu that came with the pullout engine or is it easier to use what came in his truck and do the segment swap or conversion harness?

 

The complete harness will plug right in.

No need for adapter harness or anything.

You would need to have the donor ECU reprogrammed with your vin. That's really all you need.

 

I'd use the stock computer from the truck that's getting the motor swap. Then segment swap the transmission files over. Change any tables needed for the 6.0 and tune from there.

 

I have HP Tuners so I don't think the VIN change will be an issue but knowing my luck it will be lol.

Any reason to go that route versus staying with the stock computer from the pullout?

 

Also to simplify the 80e part he picked up a 4wd unit thats been rebuilt but it is an 03. He was told by the person that he bought the complete engine pullout from that the 03 trans will not work with an 02 harness or vehicle. Is that true? I was not able to find anything that supports that, just that in 04 the went to the t42 TCU setup.

 

The internal wiring harness changed inside the transmission in 04 it will still work with his set up.

They did not use a T42 TCU on the trucks until the 07 NNBS style trucks. Still even if it came from one of those, The transmission would still work in an 02 vehicle.