4l60e or 80e in 89 c3500?

[89c3500dually]

I've searched the interweb up and down and can't find a concrete video or all helpful DIY forum answer so hopefully one of you fine folks can help me out. I have an 89 c3500 dually that I would like to put either a 4l60e or 4l80e trans into as I would like overdrive and better towing capability. Has anyone here done it and if you did please help me out with some questions such as.
1. Which is better 4l60e or 4l80e?
2. What standalone ecu did you use?
3. Did you need an adapter plate?
4. Did your engine need any additional add ons to work with the trans?
5. What harness did you use or did the factory work?
Any insight is greatly appreciated as I would like to undertake this very soon but would like to have all my ducks in a row before I start. Thanks in advance.

 

[NickTransmissions]

I've searched the interweb up and down and can't find a concrete video or all helpful DIY forum answer so hopefully one of you fine folks can help me out. I have an 89 c3500 dually that I would like to put either a 4l60e or 4l80e trans into as I would like overdrive and better towing capability. Has anyone here done it and if you did please help me out with some questions such as.
1. Which is better 4l60e or 4l80e?
2. What standalone ecu did you use?
3. Did you need an adapter plate?
4. Did your engine need any additional add ons to work with the trans?
5. What harness did you use or did the factory work?
Any insight is greatly appreciated as I would like to undertake this very soon but would like to have all my ducks in a row before I start. Thanks in advance.

Curious as to where you looked as pretty much any result that would come up in a basic "4l60e vs 4l80e" would produce hundreds of results, giving you all the info you could possibly want.

4L80E all day and twice on Sundays, esp for a towing/working heavy duty rig.

US shift or TCI for controller w/harness

No adaptors needed, will bolt right on

Grab a 97+ unit, they have better internals

Engine add-ons? Yes - super charger or twin turbo

 

[89c3500dually]

Well I guess the problem I'm having is everyone has a hundred different ways to do it and I'm wondering who has the "beat all end all worked 100%" method to madness, no one give finished feedback once they do it or how they do it I just would like some clarity.

 

[NickTransmissions]

Well I guess the problem I'm having is everyone has a hundred different ways to do it and I'm wondering who has the "beat all end all worked 100%" method to madness, no one give finished feedback once they do it or how they do it I just would like some clarity.

Well 99 of them are wrong as there's only one way. Grab a 4L80E (97+), flexplate, new torque converter and install. You'll need to move your transmission x member back a little bit (there are also bolt-in cross members available for these swaps).

Measure the distance from the rear of the output shaft to the diff yoke then take your driveline for a cut and balance.

Install your preferred stand-alone controller and plug it in. There are harnesses available in the aftermarket if the controller itself doesnt come with one for the 4L80E's two speed sensors.

Will you be rebuilding the 4L80?

 

[89c3500dually]

Well 99 of them are wrong as there's only one way. Grab a 4L80E (97+), flexplate, new torque converter and install. You'll need to move your transmission x member back a little bit (there are also bolt-in cross members available for these swaps).

Measure the distance from the rear of the output shaft to the diff yoke then take your driveline for a cut and balance.

Install your preferred stand-alone controller and plug it in. There are harnesses available in the aftermarket if the controller itself doesnt come with one for the 4L80E's two speed sensors.

Will you be rebuilding the 4L80?

Yes have full intentions on building it and upgrading torque converter, shift solenoid, and servo, maybe clutches if it's reasonable but I'm not looking to do that until I've done the swap and can fully test its reliability. Hate to dump money into a project that won't do what I need it to. Really just looking for highways speeds to match current Era so 75-85 without running 3800+ rpm amd when I tow my toys to the dunes I can do so without thinking I'm going to explode the trans. The trucks been beautiful since I rebuilt the 7.4l but now it seems the trans is my weakest link with no OD.

 

[89c3500dually]

Yes have full intentions on building it and upgrading torque converter, shift solenoid, and servo, maybe clutches if it's reasonable but I'm not looking to do that until I've done the swap and can fully test its reliability. Hate to dump money into a project that won't do what I need it to. Really just looking for highways speeds to match current Era so 75-85 without running 3800+ rpm amd when I tow my toys to the dunes I can do so without thinking I'm going to explode the trans. The trucks been beautiful since I rebuilt the 7.4l but now it seems the trans is my weakest link with no OD.

Also what tcu would you recommend I've seen a lot of EZ TCU recommendations but reliability seems up in the air.

 

[NickTransmissions]

Yes have full intentions on building it and upgrading torque converter, shift solenoid, and servo, maybe clutches if it's reasonable but I'm not looking to do that until I've done the swap and can fully test its reliability. Hate to dump money into a project that won't do what I need it to. Really just looking for highways speeds to match current Era so 75-85 without running 3800+ rpm amd when I tow my toys to the dunes I can do so without thinking I'm going to explode the trans. The trucks been beautiful since I rebuilt the 7.4l but now it seems the trans is my weakest link with no OD.

What makes you suspect it won't do what you want it to do?

Also, you don't need any aftermarket servos with the 4L80Es; those are needed for the 200-4R, 700R4 and 4L60/65/70Es.

I'd not install it then build it, that's a ton of time wasted...If you're not sure a 4L80E is right for your project, then hold off until you're sure or found a better alternative. But if you're seeking a tough four-speed auto that will take anything you will likely throw at it and don't want to mess with all the complexities and costs (for less reliability) of the six, eight or ten speed transmissions then either the 4L80E or Allison LCT 1000 is going to be the two GM transmissions that would fit the bill...

The alternative is a built TH400 with a Gear Vendors overdrive unit bolted to it...About the same amt of money, maybe a little less once you compute the cost of rebuilding the 80 and spending the funds on a good stand alone controller (TCI's is considered the 'Cadillac' of those control units).

 

[89c3500dually]

What makes you suspect it won't do what you want it to do?

Also, you don't need any aftermarket servos with the 4L80Es; those are needed for the 200-4R, 700R4 and 4L60/65/70Es.

I'd not install it then build it, that's a ton of time wasted...If you're not sure a 4L80E is right for your project, then hold off until you're sure or found a better alternative. But if you're seeking a tough four-speed auto that will take anything you will likely throw at it and don't want to mess with all the complexities and costs (for less reliability) of the six, eight or ten speed transmissions then either the 4L80E or Allison LCT 1000 is going to be the two GM transmissions that would fit the bill...

The alternative is a built TH400 with a Gear Vendors overdrive unit bolted to it...About the same amt of money, maybe a little less once you compute the cost of rebuilding the 80 and spending the funds on a good stand alone controller (TCI's is considered the 'Cadillac' of those control units).

What makes you suspect it won't do what you want it to do?

Also, you don't need any aftermarket servos with the 4L80Es; those are needed for the 200-4R, 700R4 and 4L60/65/70Es.

I'd not install it then build it, that's a ton of time wasted...If you're not sure a 4L80E is right for your project, then hold off until you're sure or found a better alternative. But if you're seeking a tough four-speed auto that will take anything you will likely throw at it and don't want to mess with all the complexities and costs (for less reliability) of the six, eight or ten speed transmissions then either the 4L80E or Allison LCT 1000 is going to be the two GM transmissions that would fit the bill...

The alternative is a built TH400 with a Gear Vendors overdrive unit bolted to it...About the same amt of money, maybe a little less once you compute the cost of rebuilding the 80 and spending the funds on a good stand alone controller (TCI's is considered the 'Cadillac' of those control units).

I think it'll do exactly what I want I guess I'm just being skittish about it since its quite the job. I'll be fabing up the x brace myself and basically doing it all by myself. I've found several 2000+ Era 80e's that I'm eyeing that have relatively low miles so a rebuild isn't exactly necessary right now if a stock 80 will pull what I need at reasonable rpm I think I'll just leave it stock and if I was to pull it to build it it's going to be far down the road so the double handling doesn't bother me. Thanks for all the help so far.

 

[NickTransmissions]

I think it'll do exactly what I want I guess I'm just being skittish about it since its quite the job. I'll be fabing up the x brace myself and basically doing it all by myself. I've found several 2000+ Era 80e's that I'm eyeing that have relatively low miles so a rebuild isn't exactly necessary right now if a stock 80 will pull what I need at reasonable rpm I think I'll just leave it stock and if I was to pull it to build it it's going to be far down the road so the double handling doesn't bother me. Thanks for all the help so far.

Yep, you should be fine if your primary concern is better hwy mpg and towing within its design limits...The 4L80E is the best GM transmission ever produced, IMO (unless you count Allison's transmissions produced when GM owned them).

 

[89c3500dually]

Cool this puts my mind at ease knowing this will be the swap I do. One more thing do you have any idea which TCI to use I'm realizing there's a handful and at varying price tags. I'm not looking to cheap out by any means I want my truck to finally have 100% potential.