Keep in mind that your 4L80E will have a different output shaft than a 4L60E, so be sure your donor has the right transmission to avoid needing to swap the transfer case input gear. Once you have ...

The NP205 transfer ... case shaft to the transmission shaft. The TH400 automatic versions used a female 32-spline input. Beginning in 1985, GM swapped over to the circular six-bolt pattern with ...