4L80 swap

Travis1027 · October 10, 2017

Just recently I had my 4L60e go out on my truck (2000 silverado 1500). I've been too hesitant to go to a trans shop as I hear terrible stories and huge bills.

While debating my options I came across a diesel shop owner who said his friend had a 'built' 4L80 with a standalone system out of a 4wd like mine.

He wants $1000, I need help deciding if this is a good route that requires little fab.

Would this bolt right into my 5.3 and transfercase?

Is the length any different where I have to worry about the driveshaft?

Do I have to flash my ecu?

Any help is much appreciated!

Mike GMC · October 11, 2017

Do you have any idea what it's out of, what year, what engine it had? If it was from a 6.0 truck, it will bolt to the engine just fine unless it's a 2000. You want a 2001 or newer for TC to flex plate spacing to be correct. I don't know about the t case. I will be watching to see if anyone knows. I may be looking at a similar upgrade soon myself. I just finished putting an 01 6.0 in my 2000 1500.

Travis1027 · October 12, 2017

On 10/11/2017 at 6:25 PM, Mike GMC said:

Do you have any idea what it's out of, what year, what engine it had? If it was from a 6.0 truck, it will bolt to the engine just fine unless it's a 2000. You want a 2001 or newer for TC to flex plate spacing to be correct. I don't know about the t case. I will be watching to see if anyone knows. I may be looking at a similar upgrade soon myself. I just finished putting an 01 6.0 in my 2000 1500.

Im not sure what its out of, the previous owner of this 4L80 bought this to replace his 4L60e he kept blowing.