4l60e or 80e in 89 c3500?

[NickTransmissions]

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.

I'd give TCI a call tomorrow and have their tech sales give you a recommendation based on your project, goals/needs for the
vehicle, etc. they can give a run down on the different feature sets for each model controller they sell so you can pick the right one for you or decide none will work and keep looking...

 

[Caman96]

OP, when @NickTransmissions talks…people listen. Kinda like this.

xc_hide_links_from_guests_guests_error_hide_media

 

[Deancr11]

Not that my opinion make a difference but I agree with everything @NickTransmissions said the 97 up 4L80e will do all your wanting the tranny to do. Hell it's just an over grown TH400 with some modern ass ons

 

[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?

Do you think a stock torque converter will be fine and will I need a different flexplate or will my 7.4 work?

 

[NickTransmissions]

Do you think a stock torque converter will be fine and will I need a different flex plate or will my 7.4 work?

Stock should be fine unless you've installed a high performance cam, then you'll want to consult your cam manufacturer on stall speed range. Current flex plate should work as long as at least three bolt holes on the TC line up with mounting holes in the flex plate; the 4L80Es converters use six total bolts.

 

[chrisahrens1]

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.

I just bought a 80E for my sport and it will take some modifications but very little. I might have to shorten my driveshaft. As fast as the computer is concerned I did a manual shift. It’s not an everyday driver anymore. It’s likely to see the drag strip more the my work place. I like to cruise it mostly with an occasional street race, but I try not to tear it up too much. But I had to go win 80E because four or 460 basically the same thing and they would not hold the power. But as far as your truck is concerned, it should both write up without any modifications other than the driveshaft like mine all depends on your wheel base. Good luck keep us posted