[elefantrider]

Has anyone put one in a B-body, to replace the th400?
What tunnel mods are required if any?
Can you use the stock th400 crossmember and driveshaft?

I'm liking the idea of having a lock up 3rd gear and OD.

[ponjohn]

You should have plenty of room, probably no mods needed.

You can program the trans to lock up at a given RPM vs gear.
So you can lock up in any gear above a certain RPM.

[HWYSTR455]

Cut the ears off, that gives plenty of room, and will clear the exhaust better.

I doubt the crossmember will work, but there are crossmembers available, or kits to make your own.

http://www.crossmembers.com/

You can get an idea of what's involve on the install tread I did for an A-body:

http://forums.maxperformanceinc.com/...=4l80e+install

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[HWYSTR455]

Another thing, on my Doug's, the collector gets kind of close to the pan on the passenger side, and I felt better wrapping that section of the collector where it runs close to the pan...

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[Steve Barcak]

Originally Posted by elefantrider

Has anyone put one in a B-body, to replace the th400?
What tunnel mods are required if any?
Can you use the stock th400 crossmember and driveshaft?

I'm liking the idea of having a lock up 3rd gear and OD.

I would ( and do ) use a 700r4. Much lass cost. I tow with 700s in my Pontiacs probably more than everyone here combined. They are great trannies.

[elefantrider]

Originally Posted by Steve Barcak

I would ( and do ) use a 700r4. Much lass cost. I tow with 700s in my Pontiacs probably more than everyone here combined. They are great trannies.

I am still considering both options. If only it only costs a little more, why not put the better trans?

What is the total cost comparison of swapping in a used, not rebuilt, trans of each type?
I have seen used 4L80e transmissions for sale at around $200-300.

The gear ratios and the .75 OD in the 4L80e are nice.

The 700r4 has a super low first gear- not sure I'd like that in my wagon with a torquey 472 ci. Also, I'm thinking the .70 OD might be too low to engage the lock-up with my current rear gears (2.73).

I have ruled out the weaker stock 200-4R for this application. This transmission's .67 OD would be too low to engage the lockup.

The goal is I don't want to open the transmission every few years or put in costly heavy-duty parts.

[David Holmberg]

You can buy the 700r4 cheaper than the 4L80e, but you'll spend a pretty penny building it to handle your TQ. The expense with the 4L80e comes with the controller, they are very proud of them.

For a driver you can go either way, just make sure you compare apples to apples.

Steve, do you have a build list to make a 700 live behind a healthy 455?

[elefantrider]

The 700r4 is very sensitive to the cable adjustment whereas the 4l80 is all electronic.

Do I have this right?

How much for a controller and who makes the best one?
Is it better to buy a speedo housing or use a box?

[kmccrystal]

Have you checked the overall length between the 2 trannies? Doesn't your B-body have the long tail THM 400? Last time I checked most of the OD-style trannies were close to THM350 in length, so the driveshaft will have to be lengthened.

OBTW, I'd love to find a direct sway for my '68 Cat with the long-tail THM400!

[elefantrider]

Originally Posted by kmccrystal

Have you checked the overall length between the 2 trannies? Doesn't your B-body have the long tail THM 400? Last time I checked most of the OD-style trannies were close to THM350 in length, so the driveshaft will have to be lengthened.

OBTW, I'd love to find a direct sway for my '68 Cat with the long-tail THM400!

Looks like there is about a 3" difference. Is there a longer yoke or extended tail housing that can be used with a 700r4 or 4L80e to make up for the difference without getting new longer driveshaft?

[Ben M.]

If you want a 4L80E on the cheap, go junkyard shopping. 3/4 & 1 ton GM trucks from 1991-1993 have the 4L80E overdrive and standalone controller. Assuming the transmission isn't why the truck is in the yard (and any yards have anything that old). Buying a standalone controller by itself is a $2000-3000 proposition from many places.

The 700R4 isn't a bad alternative, I just dislike the cable adjustments being so critical. Not to mention if it needs to be beefed up it can cost some serious money.

I don't think your engine will like the .75OD ratio with 2.73 gears based on experience of others who have tried...

[chitownTA]

Any idea how the fit would be in a 63 GP with a 4l80? How are they compared to a 400 size wise?

[marks73ta]

I have a 4L80 trans in my '93 turbo deisel GMC 2500. I also have a full disassembled 4L80 for my Catalina in the future. They both measure 31.5 from bell face to end of tailshaft. Mark L

[Sirrotica]

Originally Posted by Ben M.

If you want a 4L80E on the cheap, go junkyard shopping. 3/4 & 1 ton GM trucks from 1991-1993 have the 4L80E overdrive and standalone controller. Assuming the transmission isn't why the truck is in the yard (and any yards have anything that old). Buying a standalone controller by itself is a $2000-3000 proposition from many places.

The 700R4 isn't a bad alternative, I just dislike the cable adjustments being so critical. Not to mention if it needs to be beefed up it can cost some serious money.

I don't think your engine will like the .75OD ratio with 2.73 gears based on experience of others who have tried...

Only the diesels have the transmission ECM by itself, gas trucks have a ECM for the engine fuel and spark management and the transmission is also incorporated into the engine management ECM.

The diesels 91-93 have a fully mechanical fuel system and that was the reason for the standalone transmission ECM. You'll need the ECM, wiring harness, and engine sensors from a diesel donor vehicle.

The former Bauman Optishift, which is the unit Jakeshoe recommends and sells for his 4L80E transmission conversions is priced at $565.00 for the control unit and wiring harness. The company has recently changed it's name to USShift and you can contact them at : http://www.usshift.com/.

The other problem with this conversion is speedometer drive as the 4L80E has no provision for one as it uses a electronic speedometer, and it can be solved 4 ways,

1) a mechanical kit is sold for around $500 to attach your existing speedometer cable to a 4L80E.

2) there is an electronic controlled motor unit that can be attached to your existing speedometer and is then calibrated to your car, it is capable of transforming electronic pules from the vehicle speed sensor to motor RPMs to drive the speedometer, price under $300.

3) you can buy an aftermarket GPS speedometer which uses satellite telemetry to calculate your speed, priced at under $250.

4) use an electronic speedometer from a later model donor vehicle.


The thing is you make the investment one time and you have a stock transmission that will easily withstand 450 HP, if more is needed the upgrades are much cheaper to this transmission than upgrading 200 and 700 transmissions. Even the electronic version of the 700 (4L65E) which is stronger than the mechanical 700, needs a ECM torque dial back in my 400 HP 05 GTO so it won't tear itself apart. These transmissions (200, 700) were not designed for this much torque and horsepower by GM and require fairly expensive upgrades and then are iffy to last with much thrashing behind torque monster Pontiacs.

GM used them in light trucks and saw the writing on the wall that they needed a stronger transmission for truck duty, enter the 4L80E closely patterned from the T400 (many internal parts are the same for both T400 and 4L80E). It costs money either way to have an overdrive transmission, but that being said starting with a T400 derivative with OD, too me is a bunch wiser choice than putting a transmission in, that was designed for at the very most a 350 SB and is probably better suited to a 305, 307 olds, 3.8 buick V6, etc. Until 1990 even GM knew the 1 ton trucks needed a better transmission so until 1990 one tons used the T400 and had no OD available. If GM knew their then available OD transmissions wouldn't make it out of warranty in a 1 ton truck application, why is it we think we know more than they did and try to use transmissions designed for really light duty automotive use?

A few years ago no one in the Pontiac community would attempt to use anything other than a T400 for racing or HD street use. Even a T350 was looked at as a source of trouble behind a hot Pontiac unless it had a bunch of money and parts in it. Yet now we want an automatic that was intended for half the torque and HP that a good running Pontiac puts out to stand up to abuse too.

I also own a 93 6.5 turbo diesel K3500 dually that has 237,000 miles on it that belonged to a contractor and was shown no mercy by the people that worked for the company. It was overloaded and run on muddy construction sites because it was 4X4 and generally abused and the transmission shifts perfectly, I use it to pull my 27 foot 7,000 fifth wheel camper and anything else I need to tow or haul with it. The transmission is one thing I don't worry about, tell me if it had a 200, or a 700 transmission in it I know I'd be holding my breath waiting knowing full well that it was only a question of not if, but when it was going to puke doing what the 4L80E does without a worry day after day.

I have 2 projects in the works for street duty and the first one will definitely have a 4L80E in it, if there is enough physical room in the second one it will also have one in it.

Here is an except from a magazine article about when you need a 4L80E:

When Do You Need The 4L80E?

“The 4L80 was introduced in 1990 and was designed for ¾ ton to 1 ton trucks, and was strictly a heavy-duty unit. The basic 4L80E design was taken from the heavy-duty TH400. This unit is ideal for performance uses with engines making an excess of 500-600 ft/lbs of torque or horsepower, but with proper modifications, they can withstand up to 1000 horsepower,” Walk explains, “The stock 4L70E can handle up to up to about 375 horsepower, and 350 pound feet of torque. Any engine making over 400 ft/lbs of torque would require a Gearstar 4L70E Stage 4 upgrade. Anything beyond 500-600 ft/lbs of torque needs the 4L80E.”

I'm thinking many street strip Pontiacs fit the 4L80E criteria and a 200 or 700 are not anywhere near being able to hold up reliably to 50,000 miles without worry, this coming from a company that specializes in aftermarket transmission upgrades............................

[David Holmberg]

Good post Brad, that's always been my line of thinking as well.

I was going to do a full manual version, but that would suck for a daily driver.

[boodlefoof]

I'm stuffing a 4L80e in my '63 Tempest project. Looking forward to the day when I get it on the road.

[elefantrider]

Good info, thanks. So it sounds like $1000-1200 just to hook one up if I had one already and want to use my factory speedo. Not including a longer driveshaft or modified crossmember. Not sure if the Optishift kit comes with a throttle position sensor and brackets so need that too.

The long tail th400 is 34" long.

I see there are several different lengths of 4L80, one being 33", which should take the same length driveshaft:

http://www.crankshaftcoalition.com/w..._transmissions

[HWYSTR455]

Originally Posted by elefantrider

The 700r4 is very sensitive to the cable adjustment whereas the 4l80 is all electronic.

Do I have this right?

How much for a controller and who makes the best one?
Is it better to buy a speedo housing or use a box?

There's a bunch of new controllers out now since I did my conversion, so you would have to do your homework there. Yes, the 4L80E is electronic, and uses input from a TPS. There are several TPS retro kits out there.

The tail housings are expensive, the cable-x boxes are less, but it's better/easier to use an electronic speedo. (there are plenty of aftermarket ones) If you're intent is to run the OE speedo/gauges, then a cable-x box would be my recommendation.

A driveshaft is cake, and if you're still running an OE one, then I suggest replacing it anyway, regardless of what trans you use. I get new ones with 1350 yokes, a new slip, and u-joints for under $300. Cheap insurance.

Totally agree that a 4L80E is the way to go, and not have to worry about tearing one apart. I have over 50k miles on mine, hard miles, and it's been flawless.

Sorry, I should have read the other posts before I wrote this!

.

[hurryinhoosier62]

chitown,

I talked to a couple of the bigger shops about that conversion. They told me I would have to cut out the entire trans tunnel to make it work. Ken Crocie said I'd be better off with a TH400/Gear Vendors O/D setup, which is what I originally planned to do. His second option was 700R4.

[HWYSTR455]

What body do you have that they said would require to cut the whole trans tunnel out? They obviously have zero experience with doing the conversions. A and F bodies I would think are smaller/tighter than big cars, and they work in those bodies.

Gear vendors are nice, but you only get an extra gear. So no benefits of lockup, etc. They also shift hard into OD, and that takes some getting used to.
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