Basically the 4l70e is a modified 4l65e. The difference is that with the 4l70e GM has introduced an input speed sensor or a turbine speed sensor. To accommodate this sensor GM redesigned the pump, stator, internal wiring harness, input shaft, and the speed sensor itself that plugs into the internal wiring harness. Here are some pic's that I took when building one for a customer.
This first picture is of the input shaft. This is what the sensor reads off of.

This next picture is the sensor mounted to the pump.

This picture shows how it is bolted to the pump.

This next picture shows where the sensor comes through the pump stator to read off the input shaft. It is kind of hard to see but it is the hole in the middle on the bottom of the sleeve in the stator.

This next picture is where the internal lock up harness will plug into the speed sensor.

Here are a couple of pictures of the internal lockup harness and the speed sensor harness.

 

so other than that, thease are not any "better" than the ole' 60/65-e?

 

This is what I've been wondering as well.

 

will they work with a 60E harness? it'd be nice if it did

 

So what does all this mean when it comes to strength and longevity as compared to a 4L65E? Anything?

 

This trans is like I said very much like a 65. It did have some other parts that had ID marks on them from GM. I will have to get my hands on them and have them checked for hardness over the 65 to give a correct answer. I would be lying if I said yes. We at FLT are currently working on some new parts for the TB SS that will not be released untill spring time. These parts we are looking to put in our level 5 units and are being produced as we speek. After FLT receives them there will have to be some testing done before we will sell them or install them for the public. Understand this guy's we want to offer the best product on the market and there is alot of work/RND that goes into our units. I'm not sure if the inturnal harness will plug into your factory harness because the 70 now comes with added pins for the input sensor. I have heard that there are speedo issues at wot with a stall TC. I'm thinking that it has something to do with programing and this added input speed sensor. I am not a tuner but I'm sure someone is working on it. Vince

 

I guess the question at this point in time is, given what you've seen up to this point, do you think that after integrating the new parts from GM's 4L70E into your Level 5 transmission, that it will be any stronger than your present Level 5?

Also, I was told that some parts were upgraded to allow for higher RPM's than was available with the 4L65E. Does your research up to this point support that theory?

 

Maybe I didn't make my self clear here. The parts that were are making are for the 70, but parts that we are making are to improve on the factory parts. At this point the idea is to make the level5 stronger and also be able to install them into the 4l70e. A special input shaft for the 70 will be exclusive for the 70 and also one for the 65. We are not just taking 70 parts and installing them into a level5.

 

Can a 4L60E be converted to 70?

The 60's are getting pretty plentiful on the used market.

 

I guess it could but without the software for the input sensor, I believe it would be a waste. Just convert to a 65.