4l60e to 4l80e swap on a 305 tbi engine

[Explorateur35]

Hello I know this is not a 4x4 gm but I would need some information I can not find anywhere.

I have a 93 g20 van 305 tbi 4L60E. I want to put a 4l80e that comes from a 94 g30 van 350 tbi. I need to know if I make changes to the wiring harness and I place all the good wires in the right place on my van 305 tbi 93 to operate the 4l80e on my 305 engine if I need to reprogram the computer? I also have in my inventory of parts a computer who comes from g30 93 350 tbi. Should I put that computer on my van 93 305 to start the 4l80e?

 

[Explorateur35]

I need help please.

 

[Greg Ducato]

You could use the 93 G30 TBI computer if it had a 4L80E, the 4L60E computer doesn't recognize the input speed sensor on the 4L80E

 

[Explorateur35]

Should I just change the computer and change some wires or do I have to completely change the wiring harness? Should I change the crossmember, change the drive shaft, change the transmission cables? Is it that there would be anything to change too? Many people tell me that my 4L60E computer will be able to operate the 4L80E transmission.

 

[Explorateur35]

Do I also need to change the flexplate?

 

[Greg Ducato]

Yes to all the changes mentioned. I think you can re-pin the harness to the 4L80E connector if it has the same number of wires. Why not stick with a 4L60E? That would seem much simpler

 

[dhcomp]

Why would a 4l80e be desirable behind a 305? The 350 TBI barely makes any power, the 305 being worse.

 

[retroblazer]

Although this is old, I was wondering what it would take to do this same swap on my 94 K1500. The reason for the swap, is the rear of the early 4L60e's transmission housing are easy to crack. I went through four of them until we finally figured out that the yoke on the rear end was bad. I'm taking the trans out in the next couple of days for another rebuild. I was yanking trees out of the orchard, when it started to slip.