So I’m in the middle of my ls swap but I am looking for a 4l80 transmission. I’ve found one I am interested in but it is 1994 model. I know it will bolt up just without the 12’oclock bolt hole. But will the 94 model trans plug into the factory wiring harness of my 99 6.0?

 

Yes. No issue

 

If I recall correctly... only the 1991-1993 models had a different internal-harness/ pass-through connector.

If any of you have one of these cores... do not use the harness.
They should be replaced with the updated/ later-model harness to avoid unnecessary problems.

 

Thanks for the quick response. I didn’t want to just take a chance on a transmission that I didn’t know would plug in and I couldn’t find an answer anywhere.