700r4 or 350 turbo, ideas?

Been thinking about an engine swap in my A van. Im considering a chevy 350 setup. I can pickup a good running 350 4 bolt with 350 turbo trans for $500. And thats from a guy I trust too. Ive always wanted a 700r4 for economy. Ive pretty much decided yes on the engine, but help me out on the trans please guys? Should I buy it and run the 350 turbo? or should I look for a 700r4? what are the pros and cons to 700r4 VS 350 turbo?(All my other cars that I built for me personally I use a 400 turbo, I like the beefyness and the towing capacity, but im not goint to be towing in the van) Maybe I should even go 400 turbo, just so I only have to have 1 spare trans around instead of several?

Let me know your advice? and opinion?

(if you're wondering why put a chevy in a dodge, please dont ask, I dont want to get into that whole fords or chevies or dodges are better, its all prefrence based on the individuals experiences.) The best experiences I've had with drivetrains have all been GM. Personal prefrence only.

200R4 :-) IMHO

Since its going into an A van all the info about demensions and fit don't apply.

I run a 700R4. The difference in strenght between a 700R4 and a TH400 is almost not measurable. You would have to have both transmisions in 100% perfect condition and rum them to their extreems to find any difference. The 700R4 is the transmision of choice with the stree/performance coumity these days. You can tow all day long with them

I run a 3:23 rear gear and 26" tires. At 60 mph with the TCC engaged my emgine RPM at cruise is 1825 rpm at 55mph its down to 1675. The fuel economy is worth the extra work.

I bunny hop my van to get the front wheels of the ground and I have line lock for lots of burn outs. I beet on that trans and so far no problems.
http://s119.beta.photobucket.com/user/m1dadio/media/DSCN1423.mp4.html?sort=3&o=21#/user/m1dadio/media/DSCN1423.mp4.html?sort=3&o=21&_suid=135671567841003804187525053673


its not so complicated to make the TCC circuit work corectly in a 700R4 if you learn the little bit there is to know about it. You can make the TCC work in 3rd and/or 4th or just 4th and with the right kit you can have the sensativity of "off" and "on" be adjustable.

There is tons of stuff availible for the 700R4, TH400s are

The gearing of the 700R4 is way better for street use.

http://www.purplesagetradingpost.com/sumner/techinfo/700R4p3.html

I think the TH400 are too heavy. If I were building a big block 4 X 4 with 33" monster tires or a comercial tow truck I might consider a 400.

my 2 cents

M1D

Space: Why do you say 200r4? Do you have any reasoning behind your suggestion that I should know about? I would like to learn more about all the choices.

M1D: Im glad to know that a 700 will handle what I plan to throw at it. I know the 400 is overkill here, but the only reason I mentioned it is as I said, so I dont have to have multiple extran transes around ready as spares.
I appreciate the informative links you posted my friend. Im learning that it may be more complicated than I thought, and slightly more than I can handle without taking it to a shop. More research will help.

The easest swap will be the 350/350 trans. The 700r is great but needs a kit to be able run the electrics. Turbo 350 only needs a vacuum line. Where are you going to run this around town , highway?

4th gear is just a wee bit higher on 200r4 vs 700r4 (freeway rpm's) th350 will put you at about 3000-3300 (not good) on freeway depending on rear end. Right now w 3:36 posi in mine at 65-70 rpms are 2050-2200. My effective rear gearing is about 2:80-2:90's because of tires/wheels. IMHO

Ill chime in here also on the tranny subject=
Im in total agreement with M1 = ive had them all (trannys) and built them every which way too. 350Th - built ok with a good shift kit will last a long time - 400's same way - just beefier in torque & HP capacity- depends on what engine ur running. Now for the 200-4r's & 700r4's = the 200's are a good unit-yet!! must be built stronger to last longer- compared to a 700 unit. 700's when done correctly with updated parts are just bullitt proff- what usually happens is a basic rebuild is done & the overdrive avble is never adjusted correctly & that alone will kill that trans quickly -i mean =QUICKLY!! again - depends on what engine & horsepower & torque you will be having? Ill also add - when we build these vans = sometimes they get heavy - with all the people & stuff we load in them - an example - im doing a camper restoration= will be a medium - heavy van -with all im doing - rear end came as a posi unit with 3:73-1 ratio. Ill be installing a 700 r4 unit- mailny for highway use & overdrive capability. Thats my main concern is to get reliability & some what a better mileage than i would get with the old powerglide that was in the van. The rear end ratio should handle the weight & performance & the OD give the add'l mileage somewhat better . again depends on what engine/ power available & actual use?? Happy Vannin !!

You don't have to "Build" a 700R4. The 700R4 I am running now is not anything special. It is stock and from a 1990 C10 PU truck. The later years of 700R4 around 89 and up have factory improvments over the earlier models. Your best choice is one in the last years just before the trans went electric shift and became called the 40 and 60 LE transmisions.

Twinpilot is right, if you don't make the TCC work right you will kill the trans and it will never shift right anyway. That applies to both 200 and 700.
People like the 200 because it is the same demensions as the TH350 and so fits well into a G van and you can use the same drive shaft. However the 200 is a lighter trans and needs to be Built up for a vehicle with this GVW usage.

The shifting of gears in the 700R4 is the same as the TH350 or 400, ist all hydraulic and so iis the lock up torque converter, only the TCC circuit is electrically controlled. The TCC is driven off the 4th gear oil passage and will make havok in the valve body. If the TCC is not controlled properly the trans will think its suposed to be in forth allready and will cause rapid up shifts. The TCC needs to be controlled to only alow engagement at the correct times. Which is what you want also because it is purly to improve cruise speed economy by lowering engine RPM under light load.

The TCC circuit is not rocket sience. If you can put a set of aftermarket gauges or a sterio into you van then you can handle a TCC circuit. Its a single wire circuit with a couple control switches in line, power and a fuse. I will gladly walk you through it if you need help. You do need to remove the Trans pan only and see what you have and then maybe change a couple little items to make it what you need , then wire up the van right.It dosn't matter what engine you have.

M1D

Hmmm... This is very interesting. Ive got the engine trans being delivered jan 2. All stock used from a 70's motorhome. 350/350. He cant get me a 200 or a 700 right now, he's out. No big, I can wait. I want to clean up the motor and change a few things before I put it in anyway. Installation will be cake , a couple years back I bought one of those plastic mock up motors, and SB chevy installs have been even easier than ever before now that I can just pull the block out of the bay by hand, change something and set it back with no hoist. Im installing the 350 trans for now just to get back on the road. I will only have a week to get everything done so Ive got to make sure everything is green before I take the week off.

Application: Daily driver, slightly raised up with larger/wider tires than stock (probably about 31" no bigger) and re-installing some of the camper amenities. For all intensive purposes its going to be my "everything" vehicle, except for towing. Thats my hearses department. My hearse is my truck. lol.

Sounds like I want the OD gear from the 200, but the beefiness of the 700. Do you guys think the 200 will handle my application? I LOVE all Im hearing about the 700, but it also sounds like im already setting up (obviously just coincidentally) for the 200 by running the 350 first. Plus I want the OD gear that will give me lowest cruise RPM.

likely with the 200 u will be fine - no towing - should be ok -just get it rebuilt with good & upgraded parts - nothing worse than being on a trip & having a tranny quit!!

You can buy 200s allready built up and ready to install. In the end thats probobly the cheepest way to go.

You might look into the 1st gear ratios on that link I posted earlier.

Many people concerne about fuel economy fail to look at the 1st gear ratio and only look at highway speeds. Much poor fuel economy comes from city stop and go driving and thats where the whole 1st and 2nd gear thing comes in. This is the bigest problem with the TH350/400.

You are talking 31" tires, What rear gear are you running? You don't want to create somethong thats a dog off the line and I am talking about normal street driving.

My van has 26" tires and a 3:23 gear and with the high ratio of the 1st gear in the 700 I hardly have to push the pedal at all to move off the line with the trafic flow.

How much you have to put your foot into it off the line to stay with normal trafic flow will determine your best or worst fuel economy. Thats just as inportant or more so then Highway driving depending which you do more of.

M1D

You guys rock. Thank you. So far it looks like the 200's winning.

M1: As far as gear ratio I havent discerned that yet, I'll take a look soon when Im doing the engine. I want ground clearance for ease of repair and trips out with my 3 wheeler, so I'll modify gear ratios rather than tires. I used to build 8 3/4's all week long so no big deal. And yes my friend, I get what you're saying about the perfect start to highway ratios to tires. I had a car not too long ago that was a dog off the line. From rough no math figuring I'd say just rear ratio and tires close to a 3:23 would do allright. Up or down from there will be easy to figure once I have more info. What you got with 26" tires that thing should be a rocket off the line. My valiant had the same rear ratio with 29 1/2 tires and IT was fast!

I still think the a later model stock 700R4 is the better way.
When I said "cheapest way to go" in my previous post I meant, Cheapest way if you are going 200R4. But a stock 700R4 would still be the least expensive by a long shot.

Either 200 or 700 you are going to have to do the same TCC control circuit rigging.

And the gear ratios between a 200 and 700 are quite different. the 200 ratios are for better economy where the 700 ratios are for delivering higher torque and RPM all being lower but a little lesser on the economy compared to the 200.

look here.

http://www.purplesagetradingpost.com/sumner/techinfo/700R4p3.html

another thing to keep in mind is cooling. These vans naturally run hot, a smaller transmission is going to need extra cooling, My 700 runs off the radiator built in cooler/heater with no problems.

I have beat on that unit till I had 236* engine temp even with a 4 core cross flow rad. All that being said the last two times i pulled the pan off within about 1000 miles there was a finger nail clipping size shard of aluminum in the pan each time and I am noticing a vibration right at 1900 rpm so I think the stator is braking up in the torque converter. However that is more because of the way I run it and not an indication of the trans. I do believe if i had a 200 I would have broke it by now.


M1D

Must say =M1 is correct and with our vans being a barndoor type- sliding thru the air=?? what diff is 3% in any ratio in any OD setup going to get us in fuel econlmy?? Especially when we are pushing a minimum of 3500# weight thru the air @ 60 ++ mph?? 700r4 is the better choice i do believe

Good point guys. I didnt realize that both r4's used the same tcc cable setup. I can get a 700 and a 200 fairly inexpensively...when my guy has one. Im not EXTREMELY concerned with mpg... If I was I'd either buy a plastic clown car like everybody else does, or just ride my harley everywhere and look like a bad a$$, lol. A little economy would be nice, but Im not going to nit pick. The best choice will be the best choice regardless of the immediate savings. If you dont give you dont get, and you get what you pay for! You just gotta make sure you pay the least for the best without crossing the threshold of paying the least for the biggest joke.

Im well aware that driving a brick with a v8 is one of the worst ways I could go about economy, and thus i am only REALLY concerned with the "fuel economy-repair costs-work load" spectrum, though not in any specific order.

It sounds like the 700 wins on workload hands down in stock format. Though the 200 has the better final drive and easier install (it sounds like).

What are repair costs like on these guys? Am I looking at arm and leg deals, or is it similar to 350-400 prices on both the 200 and 700?

The TCC is the "torque converter control:

You are talking the TV cable, "Throttle valve"

And ya the TV set up at the throttle is very important to get the geometry right, but you know what? that is true for just about any auto trans you install.

Again, its not rocket science but it does take a little craftsmanship to make it right.

The little extra work it is to make the throttle linkage geometry right and the Torque converter control right is going to make the all time difference between a trans the works super nice for you or a trans the sorta works or "goes ok" or worse a trans that works so bad you believe the trans is shot.

My experience has been, if you do that little extra work to make the trans respond correctly you are going to be so happy with the way it serves you, it will be a pleasure to drive and something to be proud of.

M1D