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1996 BBB
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In as well. I really want to hear how the 6l80e fits. It seems like it would have to involve either a completely new transmission tunnel big enough to be very obviously altered inside the car or hanging it incredibly low/wacky driveline angle. I think one member did a pretty signifgant body lift. I really wanted to do a 6l90e in my car, and I figured welding up a new tunnel wouldn't be a problem but the more i thought about it, I didn't want to mess with the fitment of the carpet, center console etc... I hope I was wrong, excited to see how you make this work and how it looks when done.
 

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Fixuntilbroke, Thanks for the great info! You make it sound easy, but the one thing that concerns me is a 1" body lift is pretty signifiant and something many of us wouldn't be willing to do. How much do you think removing the 1" body lift would change the floor situation? would the trans tunnel width have to be expanded at that point or just height? I wonder if that would affect the back seat at the U joint area in the rear.
Also, what engine mounts are you using? Something that maintains the factory crank centerline like KDS or is the motor set up a bit higher?

I wonder how hard it would be to weld up some type of a skid plate off the crossmember and tie it into the chassis.
 

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Congrats on getting it to fit so easily (at least from here it looked easy :), but I know it's a lot of work!).

Is the transmission pan the lowest thing/first to hit?
If you could post some pics of the trans installed when you get a chance, it would be really helpful! maybe if you can take a quick measurement of the trans/driveline angle as well. did you have to angle the trans downwards too far to clear the tunnel?

I'm shocked, I didn't think fitting one of these would be possible using KDS mounts without really raising/widening the tunnel a great deal or having the trans hang insanely low. This is awesome news as if my 4l60e ever bites the dust, I would love to go with a 6 speed mainly for the lower OD (gear spread would be nice too though).I'm running an E67 ECU but with a T42 TCM and modified CTSV OS for a 4 speed but it would be pretty easy to set it up with the 6 speed OS.

Awesome work!
 

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i wll post some later, see post #15 how I "Modified" the transmission to fit. I did drop the transmission mount area by 1/8" or you can cut off 1/8" off the transmission mount rubber side. My biggest mod to the tunnel is that I flattened the body lip at the top of the tunnel and I used a small prybar at the transmission tail to make a little bit of room, not much maasaging is needed. Engine is sitting all the way back on KDS, if it was sitting all the way forward (must holley 302-2 pan or TSP 82073) less modification would have been needed.

If you were to go 6L go for the 6l90E (beefed up) from a 2wd truck--both 6L80e and 6L90e from trucks came with the slip yoke vs the cars came with 3 prong flange yoke(more $$$$).

Wiring is easy, connect every thing per pin out can bus data line data as follows: ECM to TCM to OBD2 port.
Nice! Thank you for that info. You're not running any type of body lift or anything like that? I'm just trying to make sense of all this as Fix Until Broke stated the following regarding his 6l80e swap (and it looks like he used a slip yoke version from the pics in the thread)

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There was "significant" reshaping of the floor pan at the back of the 6L90 to get it to clear - the metal stretched so much that there's some stress tears in it - any more and I would have had to cut/weld (as it is, they're sealed with seam sealer and painted). I have a 1.5" body lift and the engine/trans crossmember is 1.5" lower than stock too so keep that in mind for ground clearance"
 

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Fix Until Broke, ahhh that must be making some of the difference. I thought you were also running an LS engine. It just didn't seem right that one car would have a tight fit with a 1.5" body lift and another car wouldn't. 1.5" is a pretty significant amount of clearance to add into the tunnel. Did you also use the PPV trans pan?

Johnabrams62 build is coming along awesome! thank you for the pics of the trans! I have the 325mm Kore 3 setup with C6 calipers and it kicks ass. I also went to Bill Harpers rear big brake kit with C6 calipers and hydroboost for some insane stopping power lol.

That is one hell of a build though, i'm jealous of the 6 speed. It's the one thing really i wish I did with my build. IMO the 6 speed trans really do a great deal to improve drivability of a heavy car like ours not having so much drop off between shifts during part throttle acceleration. I've got a 700+HP LSA blown car with 3.73's and it still just always feels like it's lugging around town with the 60e at part throttle. Also like the .67 OD gear. It's the reason I didn't go 4l80e with its .75OD. Even with a .70OD, I wouldn't mind dropping a few RPM's on the highway with my 3.73's and 25.7" tires
 
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