I have 69 Camaro, 502 CI BBC, w/TH400 E tranny, B&M shift kit, 9" torque converter (2800 stall) Ford 9" w/ Moser 31 spline 390 gears posi Ford Explorer disk brakes. My RPM at 70 MPH is 3500 would a Gear Vendor reduce that RPM to 2500 or less and are they simple to hook up ? I heard little about these and wondering if it might be a way to go. I do not want to change any of the powertrain. Except find a way to reduce the R`s at high speed and try and save the engine a bit. Any other ideas ?

A gear vendor 0.70 OD trany will drop your RPM down to 2450, which is below your stall speed so the tranny would be slipping.

That is why I oppted for the 4L80E overdrive transmission (uses 80% of the TH400 parts so it's just as strong) with a Locking 3400 RPM torque converter that acts like a clutch at cruse speeds.

I am running a Th400/GV set up in my 69. This is with a 10" 3500 stall. Sucker works great with no much slip at all. Camaroman7D also runs a similar set up with the same results. My converter is fairly tight until you flash it. When at light cruise very little torque is being applied and the converter does not slip much at all. I am also running a deep B&M pan with a large tranny cooler. My rear gears are 3.55's with 26" tires. I also talk with Chris at CK performance about this set up and he said the same thing....run it!

GV is a .78 overdrive so you drop 22%.

LARGE TRANNY COOLER!

pdq67

Ditto what 6D9 said. I have a 3500 stall, I drive/drove my car on the highway for long dustances (several hundred miles). I never had an issue with tranny temps, had a temp gauge on it. Your converter should not be slipping at highway speeds, if it does it is way loose.

Your car is a prime candidate for a GV (IMO).

With a 0.78 final drive (sorry I thought it was 0.70) puts you at 2730 RPM which is at or just below the flash point of the converter which you listed as 2800, so it should work. I like the GV idea because you get to keep all your good parts and have OD. Only down side I can see is the lack of a locking converter.

Hello All,

I just saw this post. So let me get this straight. I can get rid of the Bull $**t T-10 manual 4 spd trans in this car and go with an old school THM400 with Overdrive? Sounds like a 700R4 only much better. I loved my THM400 in my first 1969 Camaro. That trans was a tank and I loved it.

Some of you reading this are probably wondering why I would want to get rid of a 4 spd? Easy. It's because the car was originally a P/G car. There is so much B.S. with linkages, reverse rods, reverse lights not working, shifter handles hits the console in 2nd & 4th gear etc. I absolutely despise the problems with this set up. I don't mind a manual trans in a car built in the last 15 years or if it came that way from the factory. I've had some cars like that. But when the prior owner of this car converted it from a P/G to a 4 spd alot of things were messed up. I'll spend less time and headaches putting an automatic in this car than getting the 4spd to work properly.

Ok so tell me where can I get a THM400 with O/D in it. I am looking to put a 9 or 10 inch converter with a stall anywhere from 2800 - 3200 RPM.

http://www.gearvendors.com/

The GV O/D unit is pretty much the same thing that was used in Volvos (Laycock Model J). Can pick them up for a couple hundred bucks.

The problem is that GV makes the conversion parts, but wont sell them seperately. Go figure :rolleyes:

SSG&H,

Please look into a built TH200-4R b/c they can be built to handle like 800+ hp!!

I don't think there's but a hand-full of guys running the TH700-R4 b/c they are just not as of now up to the task of handling BIG power like the TH200-4R tranny can be built to handle.

As always, jmho..

pdq67

The 200's are nice and all but if you happen to hurt it it has to go back to the "high end shop" that built it. Then you get to argue over if they plan on fixing it plus shipping bs. With the TH400....any local guy can build them right for dirt cheap. Plus I hate TV cables....JMO

Hello pdq & everyone ,

I'm a bit old school. I recall the old THM 200's in GM cars made in the 1970's & 1980's. These things were J-U-N-K!! :angry: GM put this behind a V8 in some Buick's & Chevy's while they put THM 350's behind 6 cyl Pontiac's & Olds' especially between 1977-1979.

Any trans made by GM with the # 200 in it scares me.:sad: I hope the 200-4R is not an electronic THM200 with current technology. If it is that would be like giving steroids to a 5ft 2 inch 165 lb NFL Linebacker. It would be pointless as he would get run over.

I'm familiar with the THM line such as 200, 350, 375B, 400, even the 700R4 which I had in my 1984 Z28. I loved my old THM 400 in my first 1969 Camaro. That trans (THM 400) could handle anything. :hurray:

Sorry to sound stupid here, but what did GM put the 200-4R behind? :clonk: I'm curious to know more about the 200-R4 and the O.E. applications for it.

I've heard/read that 460LE & 480LE's are used in the new Corvette's and can handle big power but they are BIG money. Is this correct??:confused:

Right you are, the old TH200, 3-speed is a real piece of work!!!!!!!!!!!!!!!!! (He, He!! I'm being nice here!!)....

Buick GN's and other vehicles have used the TH200-4R and from there the turbo Buick guys have got it to live above 800hp!!

I mailed the real Arr Carr and asked him about one to go behind my 496 after I shell my M-20 and he said 800 hp was no problem, although it will be pricey...

I can't verify it, but I don't think hardly anybody can get a TH700-R4 to live behind a 550hp BB...

pdq67

pdq,

A friend of mine who competes in some Super Chevy races advised me NOT to go with the 700R4. I currently have a 350 engine in my car with a T-10 manual 4 spd trans. He said a 700R4 probably woudln't be able to handle the 396 which was in my old car and throwing out close to 500 HP with 12.5 :1 in it, 292 duration cam and other goodies. No nitorus though. He also said the 700R4 would get killed behind a Big Inch Big Block at the horsepower I am looking to go with and would get killed behind a smaller inch big block like my old 396. It would handle the 350 that's in it now and that's about it.

He made sense. In my 1984 Z28 once that boat anchor 305 camshaft went flat around 93k miles I replaced that stock factory rated 190HP 305 with a Jasper emissions legal 305 putting out 300-325 HP. This was back in 1993 I think. Maybe 1992. They did not make a 305-350 emisisons legal conversion until about a year later. Well shortly after the trans was slipping and then in an unrelated matter the catalytic converter went bad.

He said to go with the THM 400. The problem is in my old car I had 3:73 gears in a 12 bolt and hat car would not hook up. I went 4:10 when I replaced my rear end recently. The 4:10 is not a good street gear even with a 4 spd manual T-10 trans which is what is in there now. It hooks up though.

The Buick GN's were awesome cars. I loved them back in the day when they were new and I still like them. But those 6 cyl's were only putting out about 300HP maybe 325 tops and that was in a GNX. I think the regular 1987 GN's were at about 240-250 HP. A well built 2004R may be able to withstand 800HP but a 500 cu. in big block with 800 HP l throw out more torque than a turbo charged 6 cyl will. That's why I get terrified whenever I see 200 after THM when it comes to GM. :sad:

I haven't had a trans rebuilt since the early 1990's. That was a LONG time ago. I wonder if it would be more cost effective to go with this Gear vendor THM400 or have a 460LE or 480LE built. Looks like the 700R4 is still junk behind some serious torque & horsepower.

If you asked me which one I hate more THM200:angry: or the Chevy 305, :angry: I would have to say the Chevy 305 by a narrow margin. That thing (the 305) like the THM 200 belongs at the bottom of some lake attached to a chain attached to a boat. :mad: :mad: :angry: :angry: :angry: :angry:

For sure TH400/GV or 4L80-E.......

I had a 700R4 behind my zz502 (swapped it in place of a tired 370hp 350 LT-1 'vette motor) it lasted about three months before it had to be rebuilt with clutch slipage. New clutches created a new problem; broken parts. I went through three trannies in one month, with each rebuild using stronger parts to make it unbreakable.

After I broke the third unbreakable 700R4, I had a 4L80E rebuilt with HD TH400 parts and Kevlar™ bands and clutches. It is still pulling the front wheels off the ground four years later, without a problem. It has gone through the occasional lock-up converter (clutch disk slips over time), but so far I have had two out of the three converters replaced under warranty (from TCI).


Larger Dave