Hi i have an 08 silverado single cab 4x4,it already had the 4l60 to 4l80 swap but not the wiring,and after watching several videos and researching forums my ecu connect isn't like any ,that the videos show,it's not the long red and blue numbered connector ,what am I missing,help please,trying to avoid buying the adapter.ty.

 

A pic or two of what you have would help.

 

 

This is what's in the truck,the tranny has always shifted hard but the tuner couldn't do anything with it,that's why I was trying the wiring swap because recently it's started just constant hard shifting,,bam bam bam,

 

You need a TCM for a 4L80E, that E38/E40 (whatever one it is) uses a TCM that communicates with the PCM via CANBUS.

You can't just tune this one, tuner should have known that.