Building a 1999 short bed with a 2012 6.2 and 6l80 with a 12 bolt help!
12-08-2015, 03:34 PM
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Building a 1999 short bed with a 2012 6.2 and 6l80 with a 12 bolt help!
I'm repurposing my drivetrain out of my 2012 6.2 after my girlfriend totaled it and need some help with the swap. What all will I need to do to my 1999 to get the motor tranny and rear end out of my 2012 into it. I have the complete 2012 just need to know how I will get the transmission in and motor running. I know I will need a driveshaft being that this is a single cab and my 2012 was a crew cab. My questions are what crossmember will I need for the tranny and do I use the computer and wiring harness out of the 2012 or the 1999? truck has full bolt ons and 2,800 stall with 3:42 gears so it should be peppy. Help me please
12-08-2015, 04:31 PM
#2
Formerly ScreamingL
One way is transfer all wiring over including dash
Other way is have someone covert that harness to standalone to work with the gmt800
Also rear from that 6.2 truck will be 14 bolt not 12
Other way is have someone covert that harness to standalone to work with the gmt800
Also rear from that 6.2 truck will be 14 bolt not 12
12-09-2015, 10:51 AM
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I just talked to Speartech and he made the project sound daunting. Would it be that hard to install the l92 and put a drive by wire pedal in it and tune the stock computer for the 6.2(I know I can keep the 4l60 and do this but I would prefer to have the ratio spread of the 6l80) and install the 6l80e and tune the transmission computer separately? Or would I swap out the entire wiring harness and put the dash of the 2012 in the 1999? Somebody has had to have done this prior and can offer some insight
12-09-2015, 11:43 AM
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Well it looks like the smart and easy way to do this is swap the 6.2 get the electronic adapters and go with the 4l60 or a 4l80 and forget the 6l80. I want all my gauges to work and I'm not going to the trouble of changing everything over to the 1999. My next question is what all do I need? I know I need the Lingenfelter box, cable throttle, some sort of cam sensor, the knock sensors off of the ls1 and a oil pressure sensor. Is that all I need? What am I missing?
12-10-2015, 07:36 AM
#7
The harness from your truck will work. Gonna have to figure something out on the throttle body. They make harness extensions for the knock sensors along with the cam sensor. He 4l60 wont last behind that 6.2 for long though. Also you wont be able to keep the vvt on the 411 pcm.
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12-20-2015, 05:34 PM
#9
The trans should work, but you would need to either have a harness made to connect the two pcms so you still have guages which i saw a writeup speartech did on a 6l80 into a 99-02(dont remember year exactly) or as previously stated use the dash out of the 12.... I have been thinking about this swap myself, but with a 6l90 and newer manual tcase, my 99 is 4wd and the crossmember bolts to the bottom of the frame and my 6" lift drops my torsion bars below the frame so i could potentially slide my xmember back drill holes and bolt it back where i need it..i found a comparison the other day on overall length and of course i didnt save the link but the 6l80 is less than an inch longer than the 4l60 so that really shouldnt even be an issue.... Id vote for trying to get the dash into the 99... I think it would be cool as hell to have a nnbs dash in an nbs truck even though you are going to need every module from the nnbs otherwise you run a risk of security issues and if you have to worry about emissions testing theres a whole other issue with vin, i am sue you would need to keep the vin from the nnbs in the module....
