Engine harnesses for all NA should be the same for Solstice and Sky and all years.
I do not believe that's true. The issue isn't so much the engine harness, but the ECU. 2006-7 LE5 2.4 equipped Kappas have a different ECU from 2008+ LE5s. @skersfan
is making one good Sky out of two 2.4 automatic Bluestone Skys with tan interiors and tops. One is a 2007 and one is a 2008. The engine harness and ECM are different on the two cars. He is using the 2007 unit and I have some issues on my 2007 harness and was just going to swap it for the 2008 harness but found out we cannot.