4l80e swap questions???

[LONG 2B LOW]

Ok, so a month ago my 99 NBS Silverado lost its 4th 4l60e, my truck has a
4.8 and is 4x4 with the autotrac transfercase and I'm considering a 4l80e swap, I'm really trying to avoid going back to a 4l60e because they are basically a time bomb and I don't want another one that's just gonna break down the road, I'm aware of the gearing differences and realize that I will be sacrificing some fuel mileage. as far as the mechanical aspect and the x-member fab I can handle all of this, the part I am unsure of is the segment swap in the pcm, I don't know of anyone that programs so I have no one to consult on this issue but what I have been told so far is that a 4x4 4.8 equipped truck has never been backed by a 4l80e so there's no available program to swap in the pcm. I know that expess vans have had 4.8's with 4l80es but obviously not
4wd. if anyone has any knowledge of this being done or of literature on this swap I would really appreciate hearing about it. thanks in advance.

btw I know this has been done with trucks that are turbo'd and there's not much useful info there for me since these trucks have full tuned pcms or stand alone tcms, I'm attempting to avoid a full custom tune

[69gmcc10]

I would send an email to black bear performance and see what they have to offer. They usually respond within a few days. You could also check out 150tunes.com to see what they can do.

[LONG 2B LOW]

Thanks for the info I will check out both of those.

[Vintage Windmills]

I blew a 4l60 in my nbs '99 so I feel your pain. That said, I'd get a 4l60e built with uprgraded internals for behind a 4.8. A 4l80e will probably zap more power than you'd want out of the 4.8. A good built 4l60e could live a very long time behind the little brother LS I would think.

[69gmcc10]

Having given you the information on who to contact I agree with Vintage Windmills on keeping the 4l60e for 2 reasons. First, I just sold a 5.3 for a 6.0 with the same rear gears and the move from the 4l60e to the 4l80e is much more significant that you think. I miss that lo first gear and I am sure you will feel that way even more with a 4.8 trying to push that big trans. Second, with upgraded rebuild kits and the available 4l65e (that they use behind 6.0 in the max to handle the abuse) there are cheaper and easier options for you choose from that you will be happier with that the 4l80e and a 4.8l.

[nekkidhillbilly]

4l65e would be a better idea or built 60. the 80e is a little work to get to fit.