700R4 opinions

I am talking to a guy now who has a 700R4 with the torque converter for 475.00.  He said he would take 450.00 with trade in of an old transmission.(does not have to be a good transmission)  The 700R4 has been completely gone through and worn parts replaced.  It has also been painted. Does this sound like a good deal.  Do you think it would be worth that amount for the fuel savings?

I think your biggest concern will be the need to shorten the driveshaft, whereas a 200-4R will reuse the driveshaft as-is, so that cost should factor into your decision.  If it's a lockup converter, you'll also likely want to get a lockup switch kit for it to take advantage of that.

My driveshaft is already shortened as I have a long tail shaft tranny from the truck I took the engine from.  

It is a lock up and I am looking into that as well, just not sure where to start.

Looks like I'll luck out too, I have a long tail T350 in her now

Are these OD transmissions better off with a lower or higher rear end gear ratio?

Also, is a lock up converter absolutely necessary with the 200/700/4L60's?

You say the trans has been gone thru, there are certian parts that need updating to make the trans stronger. The question is, did they do those updates. I will try to find a link that lists those parts. JB http://transmissioncenter.net/700R4_Swap_Info.htm

My 77 has one in it and I've gone through the old rear ratio of 2.73 and currently running 3.42.

Some major considerations:

On the old rear gears, the 3 to 4 shift liked to happen at a pretty low RPM which for me was roughly 60 MPH. That is to say that the car wanted to shift back down into 3rd from OD. This is a pretty typical cruise speed and you will know quickly if your lock-up is not working. If your lock-up is not working correctly, expect your 3 to 4 clutch bands to die quickly with those ratios. Make SURE it works.

City mileage will drop. It can't be helped, the 1 to 2 shift is a pretty big leap and you will turn some decent RPMs before it happens.

Highway mileage will improve. Overdrive, duh.

If you ever have fun with your car, overdrive/4th is not a gear you can accelerate in without aftermarket parts. Any attempts to do so will just kick you back down into 3rd no matter what and can cause seriously high RPMs when you don't want them.

If you have any kind of power and plan to run the car even moderately hard, expect a stock config 700 to die fast.

With the 2.73 rears, the car drove the highway at under 2000 rpm. It was VERY efficient. With 3.42, you will run at just over 2000 rpm and you'll notice the hit, but the ratio helps calm down the extreme first gear for a street car. If you're wanting to do some racing, 3.73s feel like 4.10s, so on and so forth. 

It helps to have a good powerband. Again, the 1 to 2 is nearly a cut in half. If you make crappy power at either end of the RPM range, you're not going to be running optimal.

I guess to sum it up, I think the 700R4 is perfect for the moderate powered street rod. It's an improvement on a stock G3 but it's not perfect, and there are better options out there for a race car of any purpose.

Installation is pretty simple. I had to move my crossmember back just a little and cut my driveshaft down by 3 inches.

A 700R4 is something I've been interested in for a long time, but havent gotten into yet. I do remember something very important though, and that you need to have a certain kickdown cable from your carb so you dont burn up the transmission.

I was told that it comes with everything I would need except the kit to work the lockup.

I am thinking more and more about a 5 speed.  I am just concerned about the peddle setup.  Not sure how all of that would work.