As suggested by @Tonyrodz , I'm going to do a build thread on my 99 Hoe. I've already done a few things, but I will start with the LS swap in this thread. So I've decided to pull the trigger and do a 6.0 swap. I've done research, but still have questions. First off, I'm going to keep the 4L60E that I have til it blows, then either build it further or swap a 4L80E (or a 5 spd upgrade). I'm not 100% sure what my trans is built with; however, the previous owner said "it's built". We all know how that goes... I bought a 2005 6.0 from a Yukon, with all accessories including harness and PCM. Will the PCM need to be retuned, since it was made for a 4L65E, or are they practically the same, besides beefier internals? The engine is going to get torn down, dipped at the machine shop to have it cleaned, inspected and all seals replaced. The heads will be getting some work done to them, along with a new cam and springs. Should I go with a custom cam, or does anyone have any suggestions? I have stock stall converter, 3.73 gears and 35" tires. Looking for a decent lope at idle and good fuel mileage. By good, I mean currently around 12-14. I would like to stay in this range, if possible. I've looked into TSP220, 225/236 Hot Cam, BTR Stage 4 224/230, and many more. I'm thinking the larger cams may bring the powerband too far up in the RPM range for my gearing/tire size/stall; however, correct me if I'm wrong. I MOSTLY daily drive, with occasional towing. Also, any suggestions on head work for the stock heads besides a spring upgrade? Porting, decking, etc. All work will be happening in my friend's shop who builds race cars, so access to tools will not be a problem. They will be doing most of the work, but I will be involved after hours when I'm done at the office and on the weekends. It's going to be a fun project, and cannot wait for it to be done! Any other help and input for this swap would be appreciating, thank you!