Because all applications are a bit different, I thought I would share my progress in an effort to … 1. Make sure I’m on the right track, and 2. To try to help other’s wishing to do the same with similar applications. I have been consolidating all the info I obtained from dozens of different Internet sources to save time when I actually get busy with the swap. It’s my hope that perhaps (even with my limited expertise) sharing here will shorten the research needed by people who come after me. I’ve never done this before so this is not intended as a how to. First the basics. My truck is a 2002 Tahoe 4x4 with a completely rebuilt 5.3 making in the Mid 300s right now. I will be putting a turbo on after the transmission with a goal of around mid 500s and keeping it a street-able daily driver. For other noobs like me, my truck falls in the category of NBS (New Body Style) and GMT800. So here’s a short list of stuff I know has to happen to do this swap: Get a 4L80e 4L80e Torque Converter Flexplate and adapter New Crossmember or Modification of Existing Swap Transfer case input shaft to a 32 spline or get a TCase from an 80e in a junk yard Longer front drive shaft Shorter rear driveshaft Dipstick tube Rewire or Buy Wiring harness adapter PCM reprogram Trans cooler lines need to be lengthened Shorter Transfer case Adapter and seal Knowledge that 80e has a taller first gear, and the rest of the gears are closer ratio Use NSS from existing 4L60e and wire harness Here’s where I am in the purchasing process (Using the list from above, I will elaborate on each): · 4L80e – Got a reman. Got it from Transmission Depot in Hudson, FL (they were amazing in helping me and answering all my dumb questions along the way) · 4L80e Torque converter – I Got a GM 278mm with a 3000 stall with billet front end from Circle-D (Another awesome vendor. Never lost patience with me with my limited knowledge of this whole process). Circle D can make a special front end with the same 3 bolt pattern as a 4L60e so you don’t need to buy the 6 bolt flexplate and spacer. If you just get a 4L80e Torque Converter with the 6 bolt, remember that you will need the 6 bolt flexplate · New Flexplate – As just mentioned, the Circle D Torque converter I bought uses a Dished style LS flexplate from a 4L60. My stock one was in rough shape so I sprang for a Hughes (4004x) · Crossmember – I plan on welding on steel angle iron to extend it the 2.5 inches it needs to use the existing crossmember · Transfer Case – For my build, I don’t need to do anything. Trans Depot built my 4L80e with a HD hardened 27 spline shaft · Longer Drive Shaft – Picked up a 15182094 on eBay · Shorter Rear Driveshaft - Had my stock one shortened by Universal Driveshaft Service in Charlotte, NC · Dipstick tube – Bought a Lokar XTD-3518FM on Amazon · Wiring Harness Adapter – 4L60e to 4L80e Transmission Plug and Play Adapter Harness LS Swap on Amazon · PCM Reprogram – Will use HP Tuners and do a 80e segment swap from a Chevy Express 4.8/4L80e (info from Sloppy) · Transcooler lines – Thinking about replacing them with -6an Steel Braided Lines · Using my NSS from my 4L60. Took a heat gun to the connections to melt the glue and they came right apart. · Transfer Case Adapter - The 4L60e one will NOT work. I got an AC Delco 15724745 off Amazon. I also got the AC Delco 8681168 Seal (have not test fitted it yet, I will update when I do) Other random stuff I bought: · GM 15765623 COVER,TRANS CONV · ACDelco 24245110 GM Original Equipment Transfer Case Adapter Gasket · Spectre Performance 4696 Flexplate Bolt · ARP 2307304 Torque Converter Bolt Kit for GM · Lubegard 19025 Kooler Kleen Transmission Cooler Flush High Pressure Formula, 18 oz. As of now, all the old parts are out and my 4L80e has arrived. The first thing I intend to do is Flush out the lines thoroughly. My 4l60e blew up and no telling what kind of crap might be in the lines. I plan to update this thread as I make progress, I know I’ll have dumb questions along the way, but if they’re dumb for me, then hopefully getting answers will help others as well. Please feel free to comment on anything. My goal in posting this is to learn.