Hellloooooo
I am going to put in a 700R4 in my '81 (taking way longer than I hoped because of dumb things like, you know, having to spend money on food and gas and the mortgage) BUT I already have a trans to build from. My bud who is doing the rebuild tells me that the one I have is the 'ol 27 spline, whereas what I REALLY want is the 30 spline deal - from a newer V8 car or truck. And that the old one is weaker and would need lots of heavy duty massaging to bring it up to handling the whopping, bone crushing power of my 355 .....
Surprisingly, I also have a line on what I think to be this more muscular trans, in the hands of a bud who says it's mine for the taking.
Who has done what to theirs?
What should I do?
What would you do?
What would Chuck Norris do? (little joke there, it just seemed to fit LOL)

 

There were a ton of changes to the 700. I wouldn't use anything below 1989.

 

The way to recognize the stronger design cases is that the casting seam runs right thru the middle of both cooler line bosses. That should have started in '89 or so. You can get a bigger OD servo, pump with more vanes in it and a few hardened parts for durability. I have about $300 in parts plus the rebuild in the one I'm about to put in a Blazer with a strong 400. Good luck!

 

mxc, I been all through this crap with a 700 in my muncie '72 here forthe o/drive....I don't think it's a reliable tranny,....period...take a look at 700r4 sites on a search...look at the parts for sale, see the variations on the 3/4 clutch pack and the expensive hard parts like drums which fail prematurely....see the long list of mods to make it 'survive'.....

then look at the terminally stupid 3.xx first hear ratio and it shifts about 2-3 seconds into takeoff so the engine boggs unless you have DPFI, but even then....it's a huge rpm/power drop off....then you get into the width and weight situation....I had to modify my tranny tunned some 2" into the lower pass side to get it to fit without violently rubbing...

then again there is the small, more easily rebuilt, lighter, more effective, more RELIABLE 200 4r tranny, same tail shaft length as any stock C3 tranny SO you don't have to shorten the drive shaft...another 100 bux savings....the 200 also takes the 350 output yoke so it's compatible with a thm350 but not a muncie or thm400...

your choice.....IMO, junk the 700 for whatever, and get a 200 4r out of a monte or something...

Oh, BTW Oliver here has done 10.5 second runs with a super engine C3 and a 200 4r turbo....

 

I have the old 27 spline, and it has been highly modified. It has never failed me, knock on wood, where the old TH350 failed me twice. I did my 350 to 700R4 mod before the newer 30 splines came out, but since you can make the decision now before investing too much money, get the newer tranny.

 

I've put a 90 Corvette 4L60 (700R4) in my 81. This should be the best stock 700R4 around and with the power an 81 produces it shouldn't be a problem. As said before if you want a 700R4 take one from after 88/89. From 88/89 the 700R4 got some upgrades and was called the 4L60 (but everybody still says its a 700, in 93 the first 4L60E came out, big difference) If I'm right the newer 4L60 should have the rpo MD8 on the right side. Also try to get a 700 from a Corvette, some internals should be better.
If I would do it again... keep the 700 I would go 6 speed!

Greetings Peter

 

I have to disagree. The 700R4, when built right, is one of the best upgrades you can do for a C3. Mine was built by Bow Tie Overdrives, a Stage II. As I mentioned in another thread the TV cable is 99 percent of getting a 700R4 to work correctly. If you get the TV cable set right and get the governor set right the ride is amazing.

My 700R4 does not shift into 2nd until up over 15 mph and when it does it's hard enough to jerk you around - even at light throttle. At full throttle the transmission will "bark" the tires in 2nd gear and even "chirp" them going into 3rd. And that's with 275/50 wide tires.

I had a local shop put a 700R4 in my car and it was never right. I ended up smoking that trans because the shop didn't know enough about the TV cable setup and the trans flipped in and out of lock, shifted too soon and bogged the motor.
I said the hell with that, junked the first one and bought a new trans, converter and tv cable setup from BTO. Best $1500 EVER spent on a car.

If I ever build another project car it will have a 700R4 in it -- you can not beat them for that low first gear launch and that overdrive. I love cruising at 75 MPH and 2200 RPM, even with 3.70 gears.

I would suppose that a 200R4 would be just as good. It's pretty much the same trans with a shorter tail shaft. The big issue is getting the TV cable right and having a governor that isn't way off.

 

I'm running a 4L60-700R4 tranny from Gearstar in shark n I luv it......Jerrylee///

 

I'm running a '92 4L60 in mine. I have been very happy with it. You MUST adjust the TV cable immediately, not when you get around to it. You do want the '88 up as noted which have the most upgrades. My '95 Suburban has over 200k miles on the 4L60E which shares much of the internals with the 700R4/4L60. Stay away from v6 versions from S10 and Astro.

 

Ahh thanks for all the replies
If the other is indeed a newer version, I'll be getting it - it's a freebie, so it gets the nod