So now that i've blown my 5th and final "Built to the max" 4l70e, i figured its time to go to the 4l80 and hopefully have no more problems. I recently swapped in a LS3/525 from gmpp and it is just killing the trans with the 35" tires. What is needed for the swap? I know the drive shafts have to be lengthened/shortened, Cross member fab will be required, wiring harness from 4l70-80 (patc sells one) as well as the transfer case adapter and shaft to fit the 70e case, a flex plate, and of course tuning. am i missing anything? or is this swap fairly easy to do in the nnbs trucks as long as you use the the 70e transfer case?

 

Im not exactly sure about this but i think the reluctor wheel may need the conversion kit or changed out. unless your getting a new 4l80 which im not sure about that. hell my advice isnt helping much im just typing. i no that the 24x and 58x reluctor wheels will play a factor in this setup somehow.

 

No reluctor wheel changes needed.

I'm doing the swap right now on a 2wd NNBS, I can't help you with the 4wd part, but the only difference between a NBS and NNBS is the wiring in the connector, and tricking the tcm into thinking it's an 08 Express van.

Unfortunately for you, I haven't read of people getting the 4wd models to work. Maybe some have by now, I was reading threads from 2010-11, but I know then they were having issues with the input/output shaft in the transfer case, then they swapped to an HD transfer but it wouldn't communicate with the dial type 4wd selector.

I've used these two threads for nearly everything I've needed to know.

4L60E to 4L80E conversion in a GMT900

https://www.performancetrucks.net/fo...-4l80e-424904/

 

see im glad someone that's did this came in here. i was looking at putting a l92 in my truck on a 4l80 and i think i was gonna run into that problem. thats i was thinking that about the reluctor wheel

 

What year is your NNBS?