4l80e/NP205 Swap

[bilfman]

I have found the rare 1991 4L80e/NP205 combo and am taking the plunge and putting into my 79 dually 4x4. I have done some research on the net and have found several tips on getting the unit to work. I have wrenched vehicles for many years and have several complete restos under my belt, but this computer controlled tranny is totally new to me.

Has anyone done such a switch, I am just networking to try and have as much information as I can. I see a Throttle position sensor is required and think that I have that setup all locked in the ol brain.

Is a map sensor required? Anything else to watch out/prepare for? Sensor, electrical?

Driveshafts and crossmember are handled, that stuff I have done many times in the past.

Thanx in advance!

[Chevy1TonFun]

You'll need a few wire adaptors. 80e's have electric speedo, shift sensor, and few others I can't remember. Hope someone chimes in to give you more specifics. A map sensor should not be required, that is for the air/fuel mixture.

[andrewmp6]

I would talk to http://www.transmissioncenter.net/ see what all they say you need for the swap.I know you need a ecu to control the trans and i remember seeing a converter box that had a drive cable to make a cable speedo work with a electric trans but can't remember what its called.

[superchevy]

I swapped a 4L80/NP205 into my '72 K25...see my build thread for info on making it work.

[bilfman]

Thanx much, tranny and tcase should be in my hands this coming week. Everything helps. Going to your thread now

[superchevy]

A couple of specifics not in my thread. I hooked my mechanical speedometer cable to the speedo output on the NP205. Also, I would highly recommend using the TCI EZ-TCU to control the tranny...it is simple to install, and the handheld allows easy set-up and shift adjustments as well as a default base program so you can't burn up the tranny.
If you are running a carb, you will have to fab up a TPS switch...see my thread for a pic of the one I made.
When I switched from carb to the FAST EZ-EFI, it made everything much easier to hook-up with the built in TPS switch on the throttle body. If it's in your budget, you might consider it.
SC

[fencepost]

I seen a TPS switch in Jegs and Summitt that bolts to the carb. Holley may make it just do a search.

[54chevytruck]

I am almost finished putting a 4l80e np208 in my 54 pickup. I used an Optishift controller. Holley sells a tps sensor that works, unless you have a manual choke, then some cutting and welding is required.

[mud slut 350]

i have a 91 k3500 3+3 i bought for a parts truck has this combo it. we pulled the 6.2 out last year and if i recall right the eng had a tach and a throttle positioning sensor for the trans. my computer has a big bundle of wires on it not sure where they all go but they are still hooked up. if ya need i can email you pics pm me. idk how to post em on here. i just pulled the t case off mine to use for something else and it had a electronic speedo sensor on it.