I just picked up a 2006 TBSS, which has always been a dream to own, that had a few thrown rods. I swapped my 408/4l80E into it and came across the issue where the VSS wouldn't populate in the scanner and the cluster showed it was in 1st gear the entire time. I didn't do any prior research because I have segment swapped dozens of vehicles without issue. When the issue happened, I got on here and a few other forums and saw that this was a super common issue with a few work arounds including the PCMofNC and LC32 options (which both seem great and reliable) but I love a good challenge of figuring something out. I built my own harness, modified the stock crossmember, and used the stock driveshaft with a new yoke. The driveshaft could actually be a little longer IMO. I just wanted to share my tune for anyone else that is a DIYer. The tune isn't finalized, and I need to adjust some shift points, but it runs and drives and everything works like stock. I have a Huron Speed kit on the way, so it has stock manifolds and y-pipe (because who uses that on a 408 haha).
2006 TBSS 4L80E Tune 3.hptCrossmemeber.jpgTrans.jpgSnow.jpg