Automatic Transmission 2-Speed thru 10-Speed GM Autos | Converters | Shift Kits
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Old Sep 11, 2014 | 07:51 AM
  #1  
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Default 6L90E Rookie

Help!
I have managed to install Gen3 motors and 4 spd automatics in my 66 Nova and 65 Chevelle. I'm pretty tickled with the cars. Without help from you guys, I would have never gotten them running!
Now, I've volunteered to install a 2008 6.0 and 6L90E in a friends 86 Blazer. The motor and tranny are from the same truck. We have been promised the matching ECM and harness from the same truck (don't have it yet).
Now, I'm reading about needing the BCM?? And, I'm seeing that the TCM is in the tranny.
Can someone, in layman's terms, tell me what I may encounter with this project that I did not see in the first two. I'm good with the installation and wiring. But can I, once again, blunder my way through a gazillion HPT screens and make it go down the road? Or, should the TCM be handed off to someone with more skills? And, do I really need the BCM?

Thanks in advance for you help.
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Old Sep 15, 2014 | 11:29 AM
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Default L96/6l80

I had the same problem last spring when I bought a 6.0 out of a 2011 Silverado 2500 and a 6L80 out of a 2011 Silverado 1500. I also got a 1 year subscription to Mitchell for the Silverado and got all the wiring diagrams. The BCM controls the tap up/tap down switch so you can manually shift the transmission. I did some research and found that John Spears of Speartech Fuel Injection had a way around it. I sent him the TCM from the 6L80 and he put a Corvette tune into it. The Corvettes did not use the BCM to control the TU/TD but rather the engine ECM. If your ECM is an E38 he can also reprogram it for you. I bought a wiring harness from him and had him program both the ECM and the TCM. It was a plug and play installation and the car started right up. Be careful of the placement of the MAF sensor. I had a lot of trouble with uneven running at light throttle until I finally put in a K&N intake kit for the 2011 Silverado 2500 on the car. My car is a 1941 Chev 2 door sedan. I've driven just over 10,000 miles with it since last summer and the motor/tranny combo is great. I'll try to post some pictures. Contact John at Speartech.
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Old Sep 15, 2014 | 12:51 PM
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Default L96/6l80

Here are some pictures of the 41 Chev. We pull a 21 ft. light trailer with it. The 6 speed auto is great with its choice of gears for towing.
Attached Thumbnails 6L90E Rookie-dsc04331.jpg   6L90E Rookie-dsc04628.jpg   6L90E Rookie-p1000801.jpg  
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Old Sep 15, 2014 | 04:15 PM
  #4  
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Alex: Thank you for sharing the info about the Speartech solution because this question comes up regularly.
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Old Sep 15, 2014 | 05:07 PM
  #5  
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Yes, thanks for sharing. Cool swap and glad you stuck with it - nicely done.

Chris
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