Questions on 4L60E to 4L80E swap.

[ResourceReaper]

So I have read the great writeup here on the 60/80 swap. Since I'll be dropping in a 408 in place of my 5.3 that's in there now, logic tells me do the trans first. It would suck to drop the motor in first and blow the trans due to the added power, and not be able to drive the truck at all.

So in my 2005 Silverado 4x4 with the 5.3L and 60E trans, I want to swap in the 80E transmission. I see the basics I have to do, but there are a few things in that write up I have questions on.

Can I use my original transfer case without changing the gearing on it?

Can I reuse the driveshaft and yoke?

I took a look at the parts list in the original 60/80 swap thread, what is the bare minimum of parts that I need to get this done? Thank you in advance!

Edit:

I think a new harness for the transmission, transmission itself, the flexplate and spacer, torque converter, PCM re-flash, and the cross member modification? Is there anything else?

- Rr

[Mickeymotormount]

1) The yoke will have to be changed to the heavier duty yoke that fits the 4L80E(not sure of the # of splines). The driveshaft will have to be shortened since the 80E trans is longer than the 60/65E trans. The front drive shaft will have to be lengthened since the transfer case was pushed back by the longer trans.

2)I don't think the transfer case can be used. I would have to think you will need the heavier duty transfer case to mate up to the 4L80E's finer splined shaft.

[farmtruc]

Someone used to make an input gear for the tcase but last time I spoke with him he was making them in group orders only.
We have used them several times. Just disassemble the tcase and install the new gear.
The tcase will now accept the larger output shaft of the 80e.
You may need the case housing or tailshaft if its called for the trans as well. Can't Rememebr. Thinking the number of bolt holes are different. The piece that sits between the trans and tcase

The 80e write needs updating. Fewer parts are needed and there are various methods to accomplish the conversion.

[ResourceReaper]

Someone used to make an input gear for the tcase but last time I spoke with him he was making them in group orders only.
We have used them several times. Just disassemble the tcase and install the new gear.
The tcase will now accept the larger output shaft of the 80e.
You may need the case housing or tailshaft if its called for the trans as well. Can't Rememebr. Thinking the number of bolt holes are different. The piece that sits between the trans and tcase

The 80e write needs updating. Fewer parts are needed and there are various methods to accomplish the conversion.

1) The yoke will have to be changed to the heavier duty yoke that fits the 4L80E(not sure of the # of splines). The driveshaft will have to be shortened since the 80E trans is longer than the 60/65E trans. The front drive shaft will have to be lengthened since the transfer case was pushed back by the longer trans.

2)I don't think the transfer case can be used. I would have to think you will need the heavier duty transfer case to mate up to the 4L80E's finer splined shaft.

Hmm... I saw in the write up that they used a 3/4 ton driveshaft. Doesn't the length of it depend on your cab size?

as far as the transfer case goes, could I just go and pick up a transfer case from a 1500 HD and put in? They had the 6.0L and I'm assuming the 80E transmission.

Forgive the stupid questions. This is the first time I am dealing with doing any modifications on a RWD vehicle. This is the first truck I've ever owned that I want to modify, so there are a bunch of things I still need to learn.

farmtruc, I also saw that I need a custom harness for the transmission? Does Nelson Performance make / sell them?

Also as an after thought can the PCM be programmed off the truck? It might be worthwhile for me to purchase one if it can be done so that I can have everything flashed on it, ready to go.

[ResourceReaper]

also if I pull a transfer case from a truck with an 4L80E, how do I know which spline count I need? Is there a simple way to tell?

[Mickeymotormount]

4L60/65E has 27 teeth on the spline. 4L80E has 32 teeth on the spline.

[ResourceReaper]

Someone used to make an input gear for the tcase but last time I spoke with him he was making them in group orders only.
We have used them several times. Just disassemble the tcase and install the new gear.
The tcase will now accept the larger output shaft of the 80e.
You may need the case housing or tailshaft if its called for the trans as well. Can't Rememebr. Thinking the number of bolt holes are different. The piece that sits between the trans and tcase

The 80e write needs updating. Fewer parts are needed and there are various methods to accomplish the conversion.

You wouldn't be able to tell me who would you?

[MrHorsepowerLSx]

If you have a manual transfer case, look for the same transfer case in the 2500 trucks, stay away from the "higher end" trucks, they will come with the push button transfer cases, and a 2500hd floor shifted case should line up with the hole your 1/2 shifter was in,look at the base models, and work truck versions for your swap, don't bother "looking" for the " auto-trac" versions they will only complicate your swap with more wires and you will still have a hole in your floor to deal with. And yes the rear end yokes are different on a 2500 rear then the 1/2 ton trucks. And just swap your yokes and u-joints around an then get it shortened if need be, and then balanced.