TH400 to 4L80e swap come in

[cleansquare]

First post! Im tired of 3300 rpm at 70 on my crate th400 so im swapping in a 4l80e!

Our best local trans builder is building me an early 90's trans with a converter for $1500-1800 depending on what it needs. Should have it by wednesday. I will be using a stand alone controller for it. My truck is an 85 C20 camper special. Carburated and freshly rebuilt 350 built by me. 4.10 semi float 14 bolt rear and its current trans is a crate gm 400.

My questions are: does anyone have any feedback on this controller ill list below, its reasonably priced at like 600 for it and the harness.

http://www.usshift.com/index.shtml

Also is the 4l80e longer or shorter than the th400? I want to get a price quote on a modified driveshaft. Thanks!
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[bilfman]

I just did a 4l80e swap last year. My truck is a 4x4 so I was swapping the transfer case too. In my case I had to lengthen my rear driveshaft 1.5 inches. For a 2wd I'm not sure how yours will end up. I posted a build on it, there may be some info that can help you here.

http://67-72chevytrucks.com/vboard/s...d.php?t=537481

As for controller, I went with a TCI unit, it was easy to use and excellent all round with install and tuning. I would recommend this one for sure and it is around $600 as well. The install instructions are a breeze and their harness is so well marked a monkey can do it As you can see in my build there is a unit for converting the electronic speedo signal from the 4l80e to turn the mechanical stock speedo, this was around $300. You also need to mount a throttle position sensor. I sourced the TPS, controller and speedo converter all seperately, it was all virgin turf for me. But after getting into it more I found that TCI supplies everything you need, good 1 stop shopping.

You will also have to modify your linkage. I had to move mine back a couple inches and welded up another rod. If you have a welder and some basic resto skills, it isn't to hard.

Good luck, I sure love the 4L80!!

[cleansquare]

Thanks for the info! I will definetely consider the TCI Instead!

Do yiu tow in in overdrive with yours?
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[meatwagon83]

im swappin one i too! saving for the controller

[bilfman]

Yeah I tow in overdrive. Also the 4l80 is like a 5 speed, when the converter locks up it drops another 200 rpm. I roll about 1850 at 60 with 3.73's and 32" tires.

[meatwagon83]

bilf did you say you get 15mpg? thats my goal (highway of course) what is done to your motor? is it a 454?

[bilfman]

I got 15 on my last test, I should do much better now. I just put on some well massaged 781 heads with oversized exhaust ports, roller rockers and a extreme torque ground cam. With the 4l80 swap I was well below my torque/power band rpm wise, so the engine was labouring a bit. With the new components it really woke it up in the 1900-2300 range, I would guess 18-20 if I drove right. But....I love mashing that pedal all the time and I cruise at 75mph, so I will do a true mpg test soon.

As for what I have done to the 454, custom ordered torque cam, 781 ported portmatched heads with oversized exhaust valves, edelbrock 750, edelbrock performer, hooker headers, 2 1/2 exhaust, 2 1/2 cherry bombs with a x-over pipe.

[meatwagon83]

ok your close to what i want to do, ive got a performer intake, i want to run a 262 or 268 duration cam and i have hedmann hedders and 2.5 inch exhausts with 40 series flowmasters, also i have stock 049 heads and a 670 holley carb. do you have a stock bottom end?

ps, i have 3;73 rear gears, what do you have? that and i am 2wd, so i am a couple hundred lighter than you.

[bilfman]

Stock bottom end, 3.73 gears

[cleansquare]

Is this the controller youre speaking of?

http://www.tciauto.com/tc/tcir-ez-tcutm.html
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[bilfman]

Thats the one.

[Gregs71]

Is there an advantage to buying and building a 4sp OD tranny and (buying a computer), vs a gear vendor?? I was just curious, why you went this route vs another.

[meatwagon83]

Originally Posted by Gregs71

Is there an advantage to buying and building a 4sp OD tranny and (buying a computer), vs a gear vendor?? I was just curious, why you went this route vs another.

way cheaper!

[bilfman]

Originally Posted by Gregs71

Is there an advantage to buying and building a 4sp OD tranny and (buying a computer), vs a gear vendor?? I was just curious, why you went this route vs another.

And 1 less piece of equipment.

[cleansquare]

bought the tci controller. thanks for the recommendation!

[cleansquare]

Having some questions about the speedo control converter. Was wondering where you got yours and how much was it? I heard you mention 300, but tci wants near 500 for theres, plus you have to buy a new cable and harness? SOme help on that would be great!

[meatwagon83]

isnt there a tailshaft conversion that changes it to a manual speedo? i think street and performance has them

[cleansquare]

ended up answering my own question after reading his thread lol

[bilfman]

It is a Cable-X, bought it directly from them. Nothing extra required to install it. Comes with a speedo cable, I just set the unit to the tci specs, it is only out about 2mph at 65 so its works well.

[SCOTI]

Originally Posted by bilfman

It is a Cable-X, bought it directly from them. Nothing extra required to install it. Comes with a speedo cable, I just set the unit to the tci specs, it is only out about 2mph at 65 so its works well.

I get what you're saying above..... But for the money TCI asks for, it should be spot on.

[bilfman]

You should be golden now. Just a driveshaft and a little linkage mod and you're driving.

One thing on install of the ez-tcu. Once you have your tps hooked up make sure to read the set up voltage instructions, it is pretty easy to check with a multimeter. I had a little issue where my voltage was too high at 0% throttle. There is a range for 0% throttle, I think between .1 and .3 volts. Somewhere there, anyhow those numbers are in the TCI book. That was my only hiccup with the install.

The only other thing that I really needed to change from the stock tcu setting was the "MAX TCC TPS", if this is too low then it will unlock the converter to easy. So for instance if you are on a slight incline on the highway and put a 'little' throttle in to it, the converter unlocks, kind of like a pain in the azz downshift. I upped this to 75% and it works beautifully for my rig. I think stock setting is 40%.

[bilfman]

Originally Posted by SCOTI

I get what you're saying above..... But for the money TCI asks for, it should be spot on.

I doubt the stock mechanical is spot on. But when running a gps I found out the difference. I bet most stock mechanicals are out that much if you ran a gps, so I think the cable-x does a good job.

[cleansquare]

I bought the cable x today, and the tps kit from acculink and already bought the tci controller you recommended.