6l80e fit in a 75 280z?

[tyranie909]

I finished my LS1 and 4l60e swap this spring into my s30. Have enjoyed driving it this year. My plan this winter was to pull the motor and trans and rebuild them. Both are bone stock. Motor is going to be completely rebuilt with c/h/i. While trans is getting built up to handle more power and fix failing clutches. That was until my friend at the junkyard called and said he has a ls3/6l80e with harness and pedal out of a 2013 Camaro ss with 50k miles. I can get it for about $4300. I know the ls3 is no issue, but I can’t find anyone who has put a 6l80e. How much bigger is it than a 4l80e? My LS1 has about 180k miles on it and by the time I rebuild both it and trans with a higher stall, I figure I will have about what the ls3 pull would cost me. My Z was originally an automatic, as was the donor z28 Camaro I took the original drivetrain from. I guess I could always convert to manual and run a t56. Is a 6l80e something I can message in, or is it a major surgery not worth messing with. 

[1969honda]

I have a complete 4wd 6L80 and an F-body T-56 minus the bellhousing currently in my garage, the 6l80 is significantly heavier and bigger. I'll see if I can get some photos tonight for you. 

Keep in mind the gear ratios and what rear gear you are running as well, first is 4.xxx on the 6l80.

[Richard Oben]

If Honda is correct and it is significantly bigger, then it is doubt it will fit.  The T56 in my car is tight.  Could not fill through the Reverse light fill because it could not be removed.  Jacked up the back a lot and filled in the fill hole until I had the right amount in it.  HTH, Richard.   

[tyranie909]

I have put a 4l80e in a 240. As long as it isn’t much bigger it may fit after a little hammering. Either way I think I am going to buy the setup. He is now just going to give motor/trans/harness for 4K and I can’t turn that down. Let me know if you manage to get those measurements, that would help a fair bit. Once I get my LS1 out, I will test fit the new setup and see how far off it is. 

[66corvair]

How did the 4l80 fit in the 240? I have one sitting in my garage to put in this upcoming spring in a 280, i understand the trans tunnels is wider than the 240.

[tyranie909]

240 isn’t too bad since it has a little more room. Will fit in a 280 as well. Just requires a hammer and some love. You also have to completely remove the big rectangular mounts that run from the top of the tunnel to the bottom. That has to be done even to fit the 4l60.

Edited December 1, 2017 by tyranie909

[260DET]

For the 6L80E if you get the complete harness and computer plus are able to connect up all the sensors etc then it should work. For a light sports car though the 4L85E is a better proposition, with a 3.7 diff you will get all the speed you need, say 260 kph with a reasonable engine. Aftermarket controllers are available if you want electronic. There is some stuff around for the 6L but no real knowledge of that. Whichever way you go it's going to be good.

[tyranie909]

Already run a LS1 with 4l60e. Currently run a 3.53 rear end. I wouldn’t have really messed with it if i didn’t get it all so cheap. Worst case I just resell the motor setup for a profit and build the LS1 and buy a 4l80e to replace thr 4l60e (I hate that transmission). Junkyard is delivering it today. Will get the old motor pulled out sometime this month and begin test fitting. If it is much wider up front, I will just cut up the trans tunnel and make it bigger. Real issue is being wider further back as there is just no room to expand. 

[1969honda]

Sorry I got busy Wednesday night and didn't get a chance to take pictures. I'll try and get out there once kids are in bed tonight. JPNDave is intimately familiar with the various modern GM automatics, especially the 4L and 6L series transmissions. He's rebuilt more 4l series than he can count and a few 6l80/90s. He also installed and tuned his entire stroked 6.2L/6L80/242AMC drive train in a jk unlimited jeep he owns 

 

 

The computer is in the transmission pan itself on the 6L80/90 and the harness is part of the engine harness. TU/TD can be achieved with the proper resistors and a couple switches after flashing the computer to a Corvette tune. There are some good resources on LS1tech and a few other forums about how to achieve that function without the body control module most believe is required.  Also tow/haul mode from what I've read can be used to store a totally different custom transmission tune as it is used to changed the shift points and line pressures from the factory anyways. Think street tune when normal and in tow/haul a revised race or drag.

08 Corvette Engine TCM Conns to do tap shifting.pdf

[1969honda]

Alright, it's cold out in my garage so I used a couple straight edges and found the length of the trans, depth of the bell housing.  I  then snapped the photos so camera angle has the tape measure markings matched to the measurement points as best as possible.  One picture shows the  entire transmission length, mine is 4wd so where the 2wd has a tail cone mounted on I have a transfer case adapter, this parting line for the adapter and the transmission body is 23"  from the engine block mountings surface.  The other picture shows the bellhousing parting line is about 6 5/8" from the block mounting surface to the bell housing to transmission parting line.  At that bellhousing parting line, the transmission is about 12" wide to the outside edges of the different case webs and tabs. From the bottom of the deepest part of my transmission pan to the tallest center rib on top at the bellhousing to transmission parting line it is 15" vertically.  Hopefully that all makes sense.  If you pm me an e-mail address I can also get you the 2005 GM 6L80 service manual and a repair parts breakdown.