Skully wrote:

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Hi there can anyone tell me if a 700R4 will fit in a 66 Acadian without modifying the hump. I believe I will need to change the tranny mount and drive shaft. Any advice would be appreciated! Thanks Marty

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          The 200r4 will bolt in if if you have a power slide or a Th350.         Same external dimensions, driveshaft will bolt on.                                     You have to buy or make a new crossmember since the mount is further back.

and

A 700R4 will bolt right in just like the 2004R, you will need an adjusted crossmember either way. The 700R4 is 3" longer than the stock transmission so you will have to use a driveshaft that is 3" shorter. A Vega driveshaft will work well if you retain the 1310 u-joint for the rear end. If you swap rear ends to a 1330 joint, you can use the driveshaft from a 70-81 Camaro.

buy a new transmission cross member,and then a painless wiring kit off e-bay for a 700R4,and your good to go...

From my experience, the 700R4 is more common, and it seems that more shops can actually rebuild them.

Out of the box, as they came from GM, the 700R4's were considered (by many) to be tougher than the 200-4R's. I am couching my answer because there is usually someone who at this point starts typing a nasty-gram claiming that the 200 is just as strong as the 700 and they cite the Buick Grand National (which had the 200-4R) as proof.

i have heard from lots of people running 200-4R's with huge torque. When I looked into it though, in order to stand the huge torque, the 200's needed a cash infusion of about $3000 to $5000. You can do it, but it ain't cheap. Art Carr is reportedly the go to shop for these. Be careful though, it seems there may be more than one Art Carr out there and the one is good, the other is not. Do a web search to determine who is who.

On the other hand, it seems the 700R4 can be built for say 400 to 450 ft-lbs for a much more reasonable amount of money (say $800 to $2000). Again, it seems more people know how to do this with a 700 than a 200, so you are more likely to get something that does what it's supposed to.

As for gear ratios, here's the rundown:
TH350 2.52:1 1.52:1 1:1 N/A
TH400 2.48:1 1.48:1 1:1 N/A
700R4 3.06:1 1.63:1 1:1 -0.70:1
2004R 2.74:1 1.57:1 1:1 -0.67:1

Some people prefer low first gear of the 700. Others prefer the shorter first-to-second change of the 200-4R.

I think the 200 tends to have higher efficiency and is lighter. It can be a terrific tranny and does not require cutting the drive shaft. It bolts right in where a powerglide or TH350 was.

Personally, I like the 200-4R. I ran a used (tired) one for about a year and I liked it. It was really soggy on the shifts and getting worse fast so I wanted to get it rebuilt, but a local shop that was recommended by several people said they would prefer to go with a 700R4 because they knew them better, were more confident in them etc. So I went with a 700R4. I do like the low first gear (I have 3.08 rear gears) and so far, I've had zero problems with the 700R4. I just dislike the idea of having to cut my drive shaft...

Both the 700 and the 200 have lock-ups that can be wired in using different techniques. Both have a kick down cable and set up of the kick down is critical - get it wrong and you can fry the tranny in a very short time. It's relatively easy to set up - but it has to be done properly.

EDIT- what I called the"kick down" is actually called the Throttle Valve or TV cable. If you run a 200-4R, look for a "good one". From my observations, the ones from the Grand Nationals are considered the absolute creme de la creme and they are correspondingly hard to find and expensive. I think the one from the Monte Carlo SS is also highly desirable, but I cannot remember the pecking order after the GN. The one I had was from a junk yard and came out of a 300,000+km 4 door sedan with a 305 engine so the fact that it was a bit soggy had nothing to do with the fact it was a 200 and not a 700....

If you google "200-4R versus 700R4" you'll likely get a huge list of discussions. Everyone has an opinion. My 700 works. I am pretty sure that a properly rebuilt 200 would have done the job too, even without spending huge bucks on upgrades - but I'm only running about 380 ft-lbs of torque.

Wes

-- Edited by 66 Beau on Saturday 25th of February 2012 08:02:43 AM

Carl, is there a gearing difference or anything like that?

Good question. I thought they both had cables and the electronic speedo did not come in until the next generation - the 4L60E and the 4L80E. "E" for electronic...

But I've been wrong before.

Note that everything said previously about needing to move the tranny cross member still applies for the 200.

great information.. thanks from me as well.
Good question.

Thanks for the great input guys! I just got a smokin deal on a good Th350, so I think at this point I will just put that in. From what I have read above, it should just bolt right in as I am not sure if I will have time to do the 700 this year. Much appreciated!