6l80/90

[Dova]

Has anyone put one of these into a 67-72? I'm pricing and in the research phase of the endeavor and wondering if anyone has. Pro's and con's of it? The obvious is 6 gears to 4. Cost of the upgrade? The search i've done seems to be that you could use one of these with a 6.0 and get similar gas mileage as if you put a 5.3 with a 4L60/70/80. Any and all feedback is appreciated.

[jorgensensc]

I'm in the process of putting a 6.2 with 6l80e in my '72 suburban. Prety straightforward install. Reused my TH400 tranny mount and slid the crossmember forward and drilled new holes in the frame for it. Driveshaft slid right in with no modification using Dirty Dingo slider mounts and frame towers from a 73+ vehicle. Even the linkage is really close and will work with minor mods. Haven't driven it yet, but the 6l80e in my wifes 2012 Tahoe is smooth and shifts very nicely. Hope this helps a little.
Shawn

[Dova]

Thanks, it does help knowing that it can be done. So just a complete drop out unit out of an '09 and newer with the 6L80 should do the trick then you'd think? We had it in a '09 chevy and I liked having it anytime you put your foot down you weren't "in between gears". Going with the pull out unit did you have to do anything special to the electronics with the tranny?

[jorgensensc]

The electronics are all built into the tranny. There is not a seperate controller like the other transmission. It's internal computer speaks directly to the engine ECM. The VSS is built directly in also, so no external sensor. That may make a difference on how you set your gauges up. What are you mating this to? My best suggestion is to get the complete engine, tranny, harness, and computer from the donor vehicle. That way it all mates up well and there won't be any communication issues that may or may not creep up. I got anew harness from PSI, although there are good directions on the net regarding reworking the original harness. I just had time constraints that affected my decision. Hope that helps a little more.
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[jorgensensc]

By the way. Depending on if you already have the engine, etc, you might consider just going with the 6.2 with it. The initial outlay will be a bit more, but you get gobs more horsepower and potential for later horsepower. After spending the money on getting a 6.0 up to the same level you may break even on the 6.2. I got an '08 Cadillac escalade pull out with 48k miles with radiator, electric fans, accessories, harness, computer, tranny lines, fuel lines, tranny oil cooler, surge tank, and fuel pump for 5500.00. I think I got a fair deal. Not necessarily a steal, but not a rip off either.
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[Dova]

Well I'm in the planning phase now. I was looking at L33's but if it's going to cost that much more to get the power level to where the 6.2 is then I might as well stick with a 6.2. at 400ish hp and 415ish ft lb of torque once the computer is reflashed should be good to go without having to add any upgrades. I haven't found any available up here. My build is going to be a little over a year from now too though. So hopefully the prices drop some. With the 6.2 would you be able to use the stock a/c compressor? Do you have a build thread on this? I would want to see if there is a way to make a paddle shifter for it too.

[Dova]

Gas mileage seem fair to good with the 6.2 also which is good because that was part of the swap was to get better gas mileage plus the reliability.

[jorgensensc]

I don't have a build thread, although I need to start it. I was doing this on my daily driver and had planned on doing it fast(within a week), but as always things got held up, mainly due to parts delays.
PSI has the tap shift wiring in their harness. So I'm sure it can be done. Just not sure yet on how as I hadn't planned on running it right away. I thought the tap shift went through the BCM, but now I'm not so sure since they wired it into the harness.
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[Dova]

Yeah i'm not sure about it. I was reading on LS1tech I believe and I think speartech was doing something with the paddle shift several years ago. So hopefully they have it figured out. I need to look into it more too. What is your daily driver? It will go into a 69-70 C10 when I pull the trigger on it.

[jorgensensc]

I've got a '72 suburban 3/4 ton that had a big block and th400 in it. 6 mpg was killing me. My swap will pay for itself in 1 1/2 years in fuel alone.
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[Dova]

Yeah, I have a 70 lwb 350 that get 10-10.5 no matter how I drive it. But i'll be buying something in about a year to put it in. Hopefully I will find a 1969-1970 2wd swb with no motor or transmission so I could drop it in.

[short-t]

You will need a high hump to fit the extra size of the 6L80/90E..

[jorgensensc]

Originally Posted by short-t

You will need a high hump to fit the extra size of the 6L80/90E..

Not arguing with you, but are you sure? I just took some pics I'm going to post later and there appears to be a ton of room between my high hump and the tranny? Granted I haven't tried to install it in a low hump, and it would probably be a really tight fit, but it might work with a low hump.
Shawn
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[Nitschke]

Originally Posted by short-t

You will need a high hump to fit the extra size of the 6L80/90E..

It is a snug fit but you Dont need a high hump I'm putting one in my low hump now and it fits. It would probably be easier with a high hump.
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[Dova]

I was wondering if it would fit in a low hump but it wasn't a deal breaker either way.

[68GMCCustom]

4L85e in my truck with low trans hump...but I could reduce the drive line angle by a few degrees if it had a high hump.

[AMERICAN PICK-UP]

I have sold several late model lsx engines with this tranny on it. they work well!!! i have heard of a 67 swb with 3.42 gears getting 19mpg with this set up 5.3 with 6l80e.

[clinebarger]

Originally Posted by Dova

Has anyone put one of these into a 67-72? I'm pricing and in the research phase of the endeavor and wondering if anyone has. Pro's and con's of it? The obvious is 6 gears to 4. Cost of the upgrade? The search i've done seems to be that you could use one of these with a 6.0 and get similar gas mileage as if you put a 5.3 with a 4L60/70/80. Any and all feedback is appreciated.

The fuel mileage between the 6 speeds & 4 speeds is negligible.

[AMERICAN PICK-UP]

Originally Posted by clinebarger

The fuel mileage between the 6 speeds & 4 speeds is negligible.

according th the gm engineers the six speed set up does produce better fuel mileage. because with the lower first gear in the trans you can run a lot taller rear gear. i see several late model 4x4 trucks with 3.08 rear gears in them. for several years 3.42 and 3.73 were all you could get in a 4x4 truck. i have seen the 2014 new trucks and all of them including the 4.3 v6,5.3,6.2 engines wil all have six speed trannys in them.

[clinebarger]

Originally Posted by AMERICAN PICK-UP

According to the gm engineers the six speed set up does produce better fuel mileage. because with the lower first gear in the trans you can run a lot taller rear gear. i see several late model 4x4 trucks with 3.08 rear gears in them. for several years 3.42 and 3.73 were all you could get in a 4x4 truck. i have seen the 2014 new trucks and all of them including the 4.3 v6,5.3,6.2 engines wil all have six speed trannys in them.

The 6LxxE transmissions are great, Though they constantly upshift & downshift.

Lower RPM's do not automatically mean better fuel mileage, I have a 6 speed Allison in my '06 Duramax, I get better mileage in 5th gear at 65mph than I do in 6th.

[Dova]

Originally Posted by clinebarger

The 6LxxE transmissions are great, Though they constantly upshift & downshift.

Lower RPM's do not automatically mean better fuel mileage, I have a 6 speed Allison in my '06 Duramax, I get better mileage in 5th gear at 65mph than I do in 6th.

We had one in a '09 chevy and I didn't think it was too bad at all. I liked the way it kept the truck in the rpm range.

[jorgensensc]

We have a '12 tahoe. I did notice when we first got it that it did appear to up shift and downshift often. However we live in a very hilly area. I also felt a couple of times like it should have downshifted, but kind of hung in a higher gear unless I really put the pedal down going up a grade. I'm thinking maybe its my driving style/ speed/ grade of hill that is causing these few issues. For example, maybe because I'm going 70 on a certain grade it's in between the shift points for two different gears. And because the speed fluctuates when it drops down a gear (propelling me up above 70) and then goes back up a gear when I let off the gas to drop down to 70 ( but the higher gear doesn't have enough umphh to keep from dropping below 70) that it downshifts again, repeating the cycle. I'm hoping that when I get the suburban up and running the tuner can adjust things in the tranny to compensate for the shifting. Maybe changing shift points? I don't know, I'm neither a tuner nor well versed in tuning capabilities of these trucks.
Shawn
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[AMERICAN PICK-UP]

Originally Posted by clinebarger

The 6LxxE transmissions are great, Though they constantly upshift & downshift.

Lower RPM's do not automatically mean better fuel mileage, I have a 6 speed Allison in my '06 Duramax, I get better mileage in 5th gear at 65mph than I do in 6th.

gm engineers think that lower rpm does translate into more mpg. so to get up to cafe fuel mileage standards that is why every 2014 silverado will come with the 6 speed tranny. but when they get out in real the world we will see what happens. i have a customer that just got his 2013 avalanche performance tuned to keep his 6l80e tranny from shifing up and down in town. he is happy with it after the tune but has not checked the mileage yet.

[Dova]

Originally Posted by AMERICAN PICK-UP

gm engineers think that lower rpm does translate into more mpg. so to get up to cafe fuel mileage standards that is why every 2014 silverado will come with the 6 speed tranny. but when they get out in real the world we will see what happens. i have a customer that just got his 2013 avalanche performance tuned to keep his 6l80e tranny from shifing up and down in town. he is happy with it after the tune but has not checked the mileage yet.

In our '09 crew cab 5.3 4x4 swb with stock tires on it we seen up to 25 mpg going from Washington State to Jonesboro AR to visit family. When I go to do this swap I may have to contact you in regards to an engine. My inlaws all live in Jonesboro area out to Egypt, right in your neck of the woods.

[AMERICAN PICK-UP]

Originally Posted by Dova

In our '09 crew cab 5.3 4x4 swb with stock tires on it we seen up to 25 mpg going from Washington State to Jonesboro AR to visit family. When I go to do this swap I may have to contact you in regards to an engine. My inlaws all live in Jonesboro area out to Egypt, right in your neck of the woods.

I have a few cousins in the egypt area.