tranny swapping question

[swtman]

I have a 67 gmc 1/2 ton 2wd with a 305 v8 4-barrel mated to a th350 and 3.73 rearend.I like the power but not the rpms on the highway. I was thinking of changing the rearend gearing but a guy at work mentioned an overdrive tranny like the 700r4. But later he mentioned maybe a 200r4. He said the 200r4 would be cheaper likely and lots available and would work perfect in my truck for the kind of driving I do. I just want a good daily driver and maybe carry the odd piece of furniture or building supplies.My research has me convinced to go with the 200r4 because of the fewer modifications in the swap.Can anyone give me any advice on this tranny? Will it work good stock and be fairly relieable? Just want to be able to cruise the highway and around town in my old truck!!!! Any help would be greatly appreciated!!

[d10s69c10]

200r4 seems to be a good choice seeing as how a 700 is pretty heavy duty. its not the best but if im correct there is a 400e that has overdrive also. ever think about just going to a 3.55 or lower? would be much easier.

i went the drastic route. trying to mate a t-56 to a big block. but 1 to 0.50 ratio is gonna be sweet

[red71cheyenne]

I know some have used the 200, but I would recommend the 700 or 4L60. Overdrive is a beautiful thing, I just don't think the 200 would handle all the weight. Personally, I've already had to rebuild the 700 once, so how its rebuilt does make a difference. Keep researching and once you have all the data, make your move!

[PHAT TONY]

I've been told that a "200" is the same dimension as a TH350;makes for an easy swap.

[lowriden58]

IIRC the 700r4 is the same length and uses the same yoke as a th350 with the 9" (long shaft) trans.

[nightmare]

The 200r4's were used in the Buick GN's. They are fairly strong tranny's. I don't know how readily available they are though.

As another question, with the 700r4, is it possible to use the yoke off of a th400?

[lowriden58]

I believe the 400 uses a different yoke

[nightmare]

i was afraid of that. thanks lowriden58

[68c10guy]

i have the 700r4 and love it, cruise 70 at 1700 rpm

[lowriden58]

Originally Posted by 68c10guy

i have the 700r4 and love it, cruise 70 at 1700 rpm

what rear gears you running? ive been wanting to swap my built 350 out for a 700. right now im 60mph @3k rpms

[68c10guy]

i belive they are 3.07

[Longhorn Man]

A few things here...
its a 200 4R... not R4
It is the same length as the TH350 short shaft
The 700R4 is NOT a H.D. tranny... at ALL.

For normal daily driving, not hot rodding, not hauling/towing a lot, the 200 4R is perfectly fine.
They are more readily avalible in wrecking yards than the 700 R4.
The physical part of installing it is easy. Remove old TH350. Slide crossmember back to the TH400 position, install tranny. If the Th350 that you pulled out, was a short shaft, then you can now just install the driveshaft as is.
Chevy engines have a flat flywheel... make sure what ever you pull the tranny out of, also has a flat flywheel.
Now you'll need to get a kit to properly hook up the lock up converter, and the TV cable. If the TV cable is not hooked up EXACTLY like it needs to be, the tranny will be dead in 20,000 miles or less... regardless of what you spent on the rebuild. www.bowtieoverdrives.com has perfectedthis art, and even though you pay top dollar for there product, you get what you pay for.
If your engine is bone stock, to include the carb and intake, and you have all the original brackets for the throttle and TV cable, and it was originally hooked the the same style tranny you are installing, then you can try the 'lift and click' adjustment on the tranny. But as soon as one item is replaced the stock adjustment is no good., and usually the way of adjusting it won't work either.
As for gearing, running below 2200 or so in an old school engine, is generally not gonna get you the best MPG unless you have a torque monster of a motor. Most people have best results in these trucks with a 3.73 to a 3.42 rear gear with an overdrive.

[WIDESIDE72]

Longhorn is 100% correct. I have a 200 4r w. a 2800 rpm stall converter in my all steel 79 Malibu 2dr behind a stroker 383 (balanced) with a 8.5" 3.73 rear axle, 28 x 10.5 x15" MT ET street tires. I have run as low as 12.70's in the 1/4 mile like this, and it cruises at 70 at around 2k rpm. The 200 4r is still holding up fine. All I had done was a good rebuild, shift kit, Corvette Servo, and I forget what the part is called, but it make it hold 1st gear longer. The stock 200 4r will not stay in 1st gear, (shifts to second) even if the shifter is manually placed in 1st gear unless you install a full manual valve body (should not be an issue in your case. I would use a 200 4r in the 72 SWB I am working on, but i have a 700r4 that has been rebuilt that I pulled out of an 82 Suburban. The 6.2 diesel finally gave up the ghost at 350k+. It still ran, but didn't have enough power to get out of its way. Never had the valve covers off. (Around 4 injector pumps til I found a co. that sold a pump with no rubber disc in pump, riveted together solid inside, lasted over 150k miles). I say go 200 4r if you do not already have a trans. It will hold w/ a good rebuild, use a good add on cooler. It is quick and easy to install, Has less drop between 1st and 2nd gear ratios than 700 r4. (700r4 has deeper 1st gear than 200 4r.

[swtman]

thanks for the posts guys!!!