4L80 4x4 Extension Housing GM OE Aluminum

Description: This is a GM performance or ACDelco OE Aluminum 4x4 extension housing compatible with 1999-2007 Silverado 2500 + 3500 vehicles & Suburban 2500s which share the same transmission body as the 2003-2009 Chevrolet Express and GMC Savana 2500 and 3500 vans. When converting your G-series van with a 4L80 transmission to 4x4, one option is to trim the output shaft by 3" and attach an NP261 directly to this extension housing. Please note that while this method is possible, we recommend using this housing in conjunction with our billet adapter for various reasons outlined on that part page. Both 2WD and 4x4 4L80 transmissions feature a 32-spline output with extended splines on the longer 2WD shaft, making it a common practice among custom builders to trim it down. Designed for:  Van Side - 2003-2009 Chevrolet Express 2500/3500/4500 series vans with 4L80 Transmission (4.8L, 6.0L, 6.6L).  Note - The 4L80 transmission was used as early as 1991 and as late as 2013. We have designe