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Discussion Starter · #1 ·
I have a simple question and can't seem to find a specific yes or no answer. I have a 1989 K2500 with a bad 700R4. I have a 1997 K2500 complete donor truck with Vortec 5.7 and 4L80E. Question, can I use the PCM from the '97 as a stand alone controller for the 4L80E? Modify the harness using only connections for the transmission? I am hoping someone smarter than me can help. It's my plow truck and old man winter will be making an appearance soon. Thanks!
 

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You might have difficulty with that because you have one of the two years that is harder to program of the GM PCM's. 96 and 97 don't have as many options to program as the later model black box PCM's and I believe 95 and earlier can be programmed using a different platform. The newer 0411 PCM's will do it easily though.

It would probably be easier and cheaper in the long run to bite the bullet and buy a standalone controller. I'm not even sure if you can provide the crank trigger to let the PCM know what the RPM's are using the non Vortec block. The Vortec block has a 4 tooth reluctor wheel behind the timing chain. The 89 motor uses the signal from the distributor to provide RPM.

You could also look on Gearhead-efi.com and find a PCM from a 91 or newer PCM (stay away from 1995, but that might only be for the 4l60e), That way you can use your existing engine and run the 4l80e.

If you change transfer cases because a lot of the 97's will have the electronic cases then you may have to do some driveshaft modifications and definitely the input shaft.

That's all I can think of for now.
 

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Discussion Starter · #3 ·
Thanks for the info. I should have told you that I am using the Vortec engine also. I am using Chevy Performances Vortec intake manifold for TBI. I will be using the stock TBI and PCM. I also have a manual shift transfer case. Just seems like if I don't need the engine managment, I should be able to use just the pins pertaining to the transmission? :unsure:
 

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Thanks for the info. I should have told you that I am using the Vortec engine also. I am using Chevy Performances Vortec intake manifold for TBI. I will be using the stock TBI and PCM. I also have a manual shift transfer case. Just seems like if I don't need the engine managment, I should be able to use just the pins pertaining to the transmission? :unsure:
Why are you staying TBI?
 

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It's easy to work on, it's my plow truck, I already have it. I am a Yooper and winters are extremely cold. Never fails to start in sub-zero weather.
You always know it’s the TBI to fix, odd flex. Plus kinda hard to break somthing with 100hp, I’m kinda impressed you break somthing so under powered honestly
 
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