Transmission swap for Suburbans???

[sunnydp]

Hello, I just recently purchased a '71 Suburban. I'm loving it, definitely glad I found a good one. So now I am looking into what I can do to make improvements here and there. I'd like to possibly swap out the transmission and put in one that has more gears than the 350 in there now. Does any one have any suggestions of what to look for? I have been reading into it some and it seems like the easiest thing to do is to put in a 200R4. I've also read that some people are strongly against using that tranny. I've found 700R4 haters though too so I'm wondering if anyone has put one of these into a suburban since I have not seen anything mentioned about that swap specifically. I'm looking to do this with as little trouble as possible since this is my daily driver. It would be great to get it all done in one weekend. Any suggestions or help would be great!

Here is a photo of my newly acquired suburban.

[IAFF2407]

GEAR VENDORS UNDER/OVERDRIVE added to the 350

nice Burb

[BlueJeep]

700R4 is probably going to be your easiest, best bet. You will have to shorten the rear driveshaft and probably slide your trans crossmember back a little. Lots of guys on this site have done it in pickups, and it would be the same for the sub.

[jimbug]

I have a 700r4 in my burb.... I love it dropped my rpm's about 900 at freeway speeds. You are from my old stomping grounds... I towed my buggy and all my tools and such from SJ to PHX with my turbo 350, somewhere between the Grapevine and PHX I hurt it.... Pretty sure it was on the Grapevine Anyhow it was a lot more involved for a 4x4 but in a 2x it should be pretty straight forward like the others were saying

[Longhorn Man]

the 200 4R would be easy... push the cross member back to the TH400 location, and bolt it up. No shaft mods, no drilling the frame, nuts and bolts job.
The tough (and expensive) part is getting it set up right.
Go to www.bowtieoverdrives.com and check out what they have to say about setting up the TV cable. Even if your engine is stone stock, there is no cable set up made for that year carb and that kind of intake, so it may as well all be aftermarket stuff. Bow Tie Overdrives has the best kits and most comprehensive set up directions out there. Don't forget a lock up control kit too.
The TV cable and lock up kit will need to be done if you go with the 700 R4 or the 200 4R... the 200 is only easier to install, plus no drive shaft shop bill.
If the TV cable is not installed properly, your tranny will be dead in 20,000 miles or so. It may feel perfect by the seat of the pants, but if the line pressure is not dead nuts right, the tranny will not live.
The 700 verses 200 debates will go on for ever, much like the chevy verses ford verses dodge. Each has good points, bad points, and then some personal preferences thrown in on top.

[sunnydp]

I checked out that site Longhorn Man and it has a lot of information. I'll definitely refer to that when I get going on this project. I'm still in the research phase. What exactly does the TV cable and lock up control kit do? I've never owned an automatic before so this is all a little new to me

Also the guy I bought it from said the engine is out of another car, I forget what he said now '74 Camaro maybe, but needless to say it is not stock. It also has some mods done to it, headers,dual exhaust, 4 barrel carb and an RV Cam. I wouldn't mind keeping the Turbo 350 in it but it gets like 12mpg right now on the freeway and I'd like to get a little more efficiency out of it if I can. Plus if I am going down the highway and I floor it to pass or something the tranny doesn't engage quick enough and the engine revs pretty high. Could this be related to the TV cable not being adjusted properly? I'd like to fix that before too long!

Thanks again for the input. I'm keeping my eye out for both a 700R4 and a 200R4. If I can find a good 200R4 cheaply enough I'll probably go with that. I was worried that maybe the 200R4 wasn't a good choice for a truck since they only seemed to come with cars.

[Longhorn Man]

the problem you have now with your tranny, could be one of two things. Either your cruise speed is right at a shift point and when you floor it it has to think about it, or, your tranny is getting old and lame. The cable on the TH350 is not a TV cable, it is just a kick down cable. There operation seems to be the same, but they are not.
The kick down cable does 2 things. When you go to wide open throttle from a cruise, it'll kick it down a gear or two. Pluss, it holds it in the lower gears. If you take off from a stand still and the kick down isn't hooked up, then it won't 'hold' first very long, and second will only last a second or two, and it'll be in third.
The TV cable, while it controls those functions, it also controls the line pressure. It has to an extent, a variable rate hyd pump, and the tranny NEEDS the line pressure to jump the second you hit the throttle.
The lock up controller controls the lock up torque converter. Good for a couple hundred RPM drop when it kicks in.