Originally Posted by
WickedSix
4L80e was not behind the 6.6 duramax...ever...so I'd question the accuracy of that sight just based on that.... and the 8.1L would only have a 4l80e if it was a suburban, a van, or the 2500 avalanche...in the light trucks and the medium duty trucks it had an allison.... easiest way I know to ID your trans is to crawl under...if its a square pan its a 4L60e if it is a rectangular pan with one rounded corner.. 4L80e