I remember reading somewhere that someone makes a "unit" that attaches to the TH-400 and provides that 4th gear (overdrive.)
DO you guys know who makes that "piece" and has anyone installed it, and if you have any comments?
Thanks.

Gear Vendors makes a very good overdriive unit for about all popular transmissions. They sell for about $2500 I think. They are supose to be fairly easy to install. They can handle a lot of torque.Try www.gearvendors.com (http://www.gearvendors.com) for more info.

[This message has been edited by big gear head (edited 02-19-2000).]

Very Interesting.I book marked their site just in case.(in case my ship comes in) http://www.chevelles.com/forum/wink.gif this would be nice in my 4x4,stout v/8,456's ie: gas guzzler.....c-ya

TC # 556 http://www.chevelles.com/forum/smile.gif
Bayou State El camino
les bon temps roulez

Building and installing the 700 trans correctly is both much easier and about half the cost of a GearVendor's setup.

I did not think that 700R4 can be build to handle that much torque (570 ft-lbs.)
Does anyone have experience with 700R4 in high torque applications?
Thanks

There's a guy back east who builds the most bizarre trans setups. two 400s in line, in one car. His latest setup is a 400 in front, with a 700 behind, in a Chevelle, 454, not a slouch in the torque department.

Since the 700 is essentially a 400 with an overdrive built into it, most critical parts from the 400 that were cheapened up in the 700 will fit the later trans, rollers, clutch hubs, etc, and will make a descent 700.

If a 700 is built by a GOOD trans person who knows the tricks, it will work just fine.

I looked into this as well. I can't justify the cost of the overdrive unit when TCI sells a very complete 700R4 for $1495. I will be going the TCI route this summer to replace my T350. The TCI unit is supposed to handle 500hp. On street tires I expect there are very few engines that could break it. My .02

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Bob (Creedmoor,N.C.)
65 Vette B&M Blown, Richmond 5-speed
68 Malibu B&M Blown, Turbo 350 10" converter

check Art Carr he is a performance builder and one of the best in the world. and also check what HP he rates his 200-4r tranny at.

The 700r4 will hold in a high torque application, but why not use a 200r4? It can also hold and it is the same length as a th350 (no drive shaft length change). Also, the 1 through 3 gear ratio is better in the 200r4 (same as th350), not the big drop between first and second gear like the 700r4. On a high performance engine you wouldn't want to drop that far out of the rpm band.

Call me a doubting Thomas. I will say no more. http://www.chevelles.com/forum/biggrin.gif

Raining over there today yanniz?

Page 170 of the newest GM Performance parts catalog on the 4L60E [700R4]:

"The two-piece transmission case allows use behind GM engines that have Chevrolet V8 bellhousing bolt pattern and produce no more than 370 lb-ft of gross engine torque."

While increased line pressure and high quality clutches increase the holding power, the limiting factor is always how much torque a transmission can handle before the planetaries or other "hard" parts break. Unless a tranny builder is putting in different planetaries and input shafts, torque capacity won't change.

If the 700R4 can handle all that torque, why the 4L80E? Wouldn't you think the bean counters at GM would have choked on all the expense of adding an overdrive and lock-up to the Turbo 400 if they already had a transmission that could do the job??

I said my piece on this subject before. If you have a street / strip car making 500 FT./LBS. of Torque do not use the 700R4 it will break with sustained abuse. I don't car who built it, it's just a matter of time.

Once again, the 700 is a modified 400, and the product cheapening department at GM lessened up on some parts for use with a small block, making the lower torque 700 work with a lesser torque rating, and keeping the production costs reasonable toi them.

When a competent, knowledgeable trans builder removes the lesser parts designed for the 700, and installs the 400 parts it really needs, the trans will perform much betteer and take considerably more torque. And, this does not mean boosting the line pressures to the moon, either.

Now, when have you ever seen a 4L80 in a pickup with a half ton rating? SS454, no. It don't happen, and they are made for larger trucks and even for Diesel use, and we all know how much more torque a diesel makes over a gasoline engine.

There are people using properly modified 700s behind fairly high horsepower and torque big blocks every day, in both strip use and daily driving. Get it built by a real trans person, and it will live.

BTW, the 200 is used by lots of people behind the V6 Turbo Buicks, and they also live well when they are built right. Only one place builds this trans correctly, but I can't remember who they are. They are in the east, though.

If your 700 didn't live behind your engine, then you should find a good trans person to do it right next time.

Just my 02 from experience.

IgnitionMan, I'm talking about serious street / strip cars that race every weekend with 500+ ft./lbs. of torque and weighs near 4000 lbs. These type of cars are built for a purpose and it's not sustained cruising or gas mileage. The 700R4 is fine for that and the occasional 1/4 mile run. But anybody building the type of car I'm talking about is using a turbo or they will be soon. I'll agree to disagree.

A STOCK 1970 454 makes 500ft.lbs. of torque. HeeHee. I'm sorry, but I come from the old school and believe in using the old tried & true and proven parts. I also like the .45ACP for the same reasons. http://www.chevelles.com/forum/biggrin.gif
Rick
'68 SS 427
'66 Yenko

IgnitionMan,

Please enlighten me with some kind of reference about your posts that the 700 is a modified Turbo 400.

Because my reference material show the 4L80 as having the same 1st three gear ratios as a T400, and as it is the only other tranny using the T400's 32 spline output shaft, I may have erred by jumping to a conclusion IT was the evolved T400. If you can post something showing your opinion on the 700/T400 to be fact, I'll quit posting my opinion on the 700.

Im no expert but have read many places that the 700R4 is based upon TH350(many parts are different) and 4L80E is based upon the TH400(approx 75% of the parts are the same) Few will argue that a TH350 is as strong as a TH400 BUT there are many strong cars out there that run built TH350s W/O problems. The nice thing about TH400 or 4L80E is that they will hold up W/O any(or very few) mods)I think a properly built 700R4 can also live in a strong car.

I also think a 200-4R can be built to live. There are a lot of 10 Sec. GNs(and some 9 Sec.) that still run 200-4R. Some will say that a GN does not make the kind of torque that a BBC makes. It may not but there has to be some serious torque(and traction) to carry the front wheels like many of them do. A 200-4R "eats" less power and has great gear ratios. Art Carr site rates HP capability as: 4L80E 1200 HP.... 200-4R 1000 HP.... 700R4 800 HP

Unless you have a very serious motor and traction I think a 200-4R can be built to "take it"

Joel> I understand that Art Carr is well known and builds good stuff. Everything has it limitations. My Yenko Tech manual says that the engine makes X amount of HP and after __ amount of hours of racing, needs to be inspected, magnafluxed, zygloed, and rebuilt. How many hours,days,weeks,months,miles,years, does Art Carr say that these transmissions, will withstand this amount of horsepower/torque ratings? I seriously doubt that there would be any kind of warranty on a racing transmission.
Rick

Lingenfelter runs 700s behind his big blocks, makes lots otf torque, and doesn't break them.

Also, 3 or 4 years ago, Hot Rod Magazine ran a story on just which parts to use, all from the 400, to boost 700 performance.

When the 700 is updated, lots of 400 parts are used to make it stronger, not 350 parts, 4L80s are a completely different trans and are huge, crawl under a truck and look at one. Take your tape measure.

[This message has been edited by IgnitionMan (edited 02-22-2000).]

Well, I'm convinced and satisfied. All 700R4's are unbreakable. I know that if someone like John Lingenfelter broke one, that it would be highly publicized and probably on the 6:00 news also.
Rick

Geeze guys, you don't need to get so defensive of your opinions. It comes down to this, nobody is saying a 700r4 will never break, nobody is saying they will die right away. Any tranny will eventually die, it's just a matter of time, no matter what tranny it is. However there is no reason that a 700r4 could not be built to handle a lot of torque, the question is just how long it can handle it. Maybe a th-400 will handle it for 100 passes and the 700r4 will only handle 50. But what if you only race a couple times a year and cruise the rest, BUT he/she still has a very high horse/torque engine. IT all depends on application and opinions.

Just remember boys, just cuz somebody disagrees with your OPINION doesn't mean your wrong.

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Chris Dagenais
Saskatchewan
'71 Malibu with a home built 454!
member.xoom.com/Gandalf80/ (http://member.xoom.com/Gandalf80/)

I would not consider using a 200-4R behind a motor making anywhere near 1000 HP but it apparently can be done. I heard(but cannot confirm) they Mike Kurtz(one of the top GN 200-R builders)does warranty 200-4Rs for 6 months even if used for racing.

I mentioned the Art Carr "Power Ratings" to show that a 200-4R is in the same league as the 700R4 and according to Art Carr it is even stronger when built properly.

I like 200-4R better than 700R4 because of better ratios(IMO), easier install, less reciprocating mass(eats less HP) and less weight.

If someone is building a strip car car with big power I think a TH400 is the way to go. If you have a mostly street car that goes to the strip on occasion I think 200-4R is a great way to go. Will it last forever. NO! Will it last as long as a TH400. NO! But, it will let you run lower much lower gears and perform much better than the same car with TH400 and highway gears. If you are making really big power and want to use the car on the street I think 4L80E would be the way to go. It is very strong but VERY heavy and VERY expensive.

I have heard that the Gear Vendors O/D units are very strong but before I would spend $2500+ for one would buy a 4L80E.

Enough of this "I heard this, My friend that". I, meaning me, the person typing, owned (I sold it, it did not break!) a Chevelle with a 406 with 560hp and 523 ft lbs of tourque ( dyno'd on a real dyno, not Mr Gasket). I used a 700r4 with a non lock up torque conv, 4:20 gears, 26" tire, 2800 stall with a best ET of 11.59. For two years I raced it at the local track and drove it on the street a fair amount. It didnt break. It's still in the car (three years old). The motor is finally showing a little wear ( I sold it to a friend, so I see it all the time).They live a reasonable amount of time, like any other trans that is run hard. It amazes me that people think because its new, it cant be strong. Go ahead and suffer, but I'll take the gas mileage.

Well I have just read a lot of opinions about what trans can handle torque but not many people that run what they are recomending. I run a zz502 with a correctly built 200r4 and it is plenty strong even for 567lbs of torque. It was built right by an outfit in van nuys ca called ACT. Art Car doesn't build transmissions any more so if you order a 200r4 from art car you are getting one built fron TCI or ACT anyway. Believe me it works and shifts hard.

Why is it that a TH400 never had to have its reliability or strength defended? http://www.chevelles.com/forum/smile.gif

I also don't understand people building big blocks, dumping a ton of money into them, then worrying about fuel economy??????......

I want to go real fast with a big 4 barrel, Oh, I better let off the gas cause I'm burnin up too much fuel.............Sigh

[This message has been edited by YenkoYS100 (edited 02-23-2000).]

Interesting point Yenko.

Few of these cars are daily drivers, but toys. We slow the engine down about 30% with an overdrive, but we don't see 30% economy increase, more like 10%. If your big block gets 10 MPG normally, it'll get 11 with overdrive. If you drive 5000 miles per year @ 10mpg = 500gal. Reduce it by 10%, hell, make it 20%,=400 gal. We save 100 gal @ $1.60 =$160 year. And we've spent $2000 to change over to an weaker tranny. It'll take over 12 years for the gearbox to pay for itself in fuel savings, and it won't last that long.

Ok, for the record, I run a 570 aluminum big block, built on a ZL1 second series block, on the street, 705 horsepower, 749 ft/lbs torque, dynoed, and a modified 700 in one of my vehicles, and have had no problems with it for over five years.

I don't care what anybody thinks of the 700 actually, mine was built correctly, has given great service without any problems or hassles, and that ain't hear-say or second hand information.

Run what you want, I'll just keep having fun and no problems with my big block/700 combo.

How many miles are put on it in 5 years?

Greybeard> It makes it very clear when you look at it like that. http://www.chevelles.com/forum/biggrin.gif
Rick
'68 SS 427 Nodular Iron Case Super T10
'66 Yenko (oh, it's a 4 speed stick also)

[This message has been edited by YenkoYS100 (edited 02-23-2000).]

That's cool IgnitionMan. 570 cubes out of a ZL1. What a shoe horn you must have. GM says max bore 4.300 and max stroke 4.375. Getting a five inch stroke into that sucker must have been pretty tough.

Congratulations.

Driven at least, every day, have logged 74,000 miles, 16 yaears of operation, engine has not been apart from first build 16 years ago, added 700 5-1/2 years ago, no problems.
Longest trip I took was 3,200 miles in 7 days, still no problems.

Yes, it is a real squeeze to fit larger bores to the ZL1 engine. Think wet interlocked sleeves.

In engine design and modification, one is limited only by the lack of thought progression. I don't have any limitations in this department, and have done lots of mods others say are impossible because they make their ideas conform to other's misguidings.

I also raced (and still have) numerous ZL1 based 541 and 570 ZL1 engines, with enough stock take out and crate parts and engines to last the rest of my life. Somebody had to buy the crate engines no-one else would back when they were available. No, no ZL1 parts are for sale, NO.

Like I said, do what you want, I'll just stick to what I know, and have proven to myself, to work.

Have a nice day, I know I will, I'm going to drive my 570 now. Bye!

Y'all remember the 3 T's thread I posted up a week or so ago. Go check it out.

FWIW I know a local drag racer that has run the same T350 for 3, er 4 seasons since he's gonna run it again this year ( w/o rebuild) behind a very stout 454, 4500 stall and trans brake, slicks etc. Why? Cause the fella knows all the ins and outs of making them work well.

Yanniz, one stated benefit of the GV overdrive is that your T400 will have 6 forward gears. I don;t know why that's a huge deal, but in the articles I've read about the GV in race cars and high dollar street rods, that's often cited as an added benefit.

TRUTH, TEMPERANCE, and TOLERANCE fellas.( Yeah i'm shouting - ya'll chill )

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Chaas
Gold #62/ACES
67 SS396/L88



[This message has been edited by Gene Chas (edited 02-24-2000).]

Has anyone checked out this site ( www.700r4.com (http://www.700r4.com) )? It REALLY explains a lot and claims they have a 700r4 that can handle WELL OVER 500 HP. They're not really that expensive either.

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LXXVI

1968 Chevelle SS396-----> EVIL396
LXXVI's Webpage (http://www.geocities.com/wasitnondependent/chevelle.html)

[This message has been edited by LXXVI (edited 10-29-2002).]

WOW,
I'm gonna dig up this post for giggles....

Talk about some crack smokin' going' on....

I-Man thinking a 700 shares ANYTHING with a 400....

4L80 IS based on a Th400 and the planets, direct drum, sprag, clutches, bands, will interchange...

700 has a FEW parts that will interchange wih a Th350 like low-reverse clutches, few thrust washers.... output shaft seal...

There was definitely some misinformation going on back then....