Vortec 454 and 4l80e swap

[Thunderhawk]

Hey yall I have a 1996 Chevy tahoe affectionately named tina the tahoe but I was wondering if anyone on here has ever done a vortec 454 and 4l80e swap I know the motor will basically bolt right in and wiring and fuel is pretty straightforward but I'm curious about trans cross member such as can I use my stock 5.7 4l60e trans crossmember or do I need to use the 4l80e crossmember and driveshaft can I use my stock driveshaft without trouble thank you for the help

 

[bigfootchiro]

Hey yall I have a 1996 Chevy tahoe affectionately named tina the tahoe but I was wondering if anyone on here has ever done a vortec 454 and 4l80e swap I know the motor will basically bolt right in and wiring and fuel is pretty straightforward but I'm curious about trans cross member such as can I use my stock 5.7 4l60e trans crossmember or do I need to use the 4l80e crossmember and driveshaft can I use my stock driveshaft without trouble thank you for the help

Welcome to the forum! Yes it can be done, and it’s fairly simple. As you can tell by my signature, I did it. We pulled a vortec 454 and 4L80e out of a motorhome that had 40K miles on it and slapped it in!

You can go to my build thread here:
https://www.tahoeyukonforum.com/threads/vortec-454-4l80e-hd-swapped-1999-tahoe-obs.96236/

A few key things to remember:

1) make sure to have the PCM that the 454 engine and transmission already have, or you will have to buy another.

2) do your research. Trust me when I say that information is few and far between, because practically no one has done it or talked about it. Make sure to get wiring schematics for the 454 harness, the 350 harness, and both PCMs so you can cross reference.

3) some wires will need to be lengthened for sensors.

4) you can either buy a 4l60 to 4l80 plug conversion, or re-pin the plug yourself.

5) you CAN use your cross member, but more than likely will have to build a custom transmission mount. I’m 2WD right now, but converting back to 4WD in a week or so, so I can let you know how that mount works.

6) you will need to have your driveshaft shortened.

7) be prepared for a 14 bolt rear end swap. Trust me on this lol

 

[willxfs]

There are several good write ups on going from a 4L60E to 4L80E out there. I would google it. Some of the things I remember is the 80 is an inch or two longer so your cross member will have to be moved back. Also your rear drive shaft will have to be shortened and your front will have to be lengthened. You will need to get an additional speed sensor and wire it in to your harness and computer. I think you will also have to source a new input shaft for your transfer case if you have 4wd. No clue about 454 swaps. Good luck. Sounds fun!

 

[bigfootchiro]

There are several good write ups on going from a 4L60E to 4L80E out there. I would google it. Some of the things I remember is the 80 is an inch or two longer so your cross member will have to be moved back. Also your rear drive shaft will have to be shortened and your front will have to be lengthened. You will need to get an additional speed sensor and wire it in to your harness and computer. I think you will also have to source a new input shaft for your transfer case if you have 4wd. No clue about 454 swaps. Good luck. Sounds fun!

I have the 80 in the Tahoe and didn’t have to move the cross member back at all. We are going to do the transmission next week and slap in the NP246, so will see how that goes. I think a front drive shaft from a burb with a 80 with work, but not sure. And yes, absolutely have to shorten driveshaft and another input speed sensor.