727 gearbox

[Jakke]

What is best year? ( strongest )
ID. number?

[DartGT66]

It isn't year dependent. I would say that any non lock up would do. There are some features in some years transmissions that are more sought after than others, but bigger differencies in the various levels inside the same year. '71& up has a better pump and front drum with a wider bearing and oil slots in the drum that flow more than the older two holes. Kick down servo is better in teh older transmissions. We have not really paid much attention to these things, and our transmissions have worked pretty well. Any year trans can be made to hold up at lest 800 hp if the traction isn't spectarcular, and if there is no trans brake. After that (it's wise even before) you have to go after aftermarket parts, and that's a point where it starts to cost. Aftermarket planetaries and front drum is most likely the first upgrades, but the list can go on and on and itäs no big deal to spend about 3000$ in parts to make a 727 bullet proof

[rumblefish360]

I heard push button units are very good to mess with.
(Feed back anybody?)

[cutting torch]

The pushbutton trannies have a smaller input shaft and front drum support.

torch

[eckertt@epri.co]

DartGT mentions to stick with non-lockups.

Can somebody elaborate why a lock-up torque convertor is bad? I am going to guess that the answer is that a lockup just can't handle high torque because of the lockup clutch, but in the low gears, the lockup won't engage.

I would love to be educated on this.

Thanks, Tim

Tim Eckert
72 Cuda 360/904

[dwc43]

Lock ups are just as good as non lock ups. The only reason some people suggest that is there are a limited amount of on the shelf stall converters for them, but you can get anything built for one if you like.

[DartGT66]

You can't get as effective hi stall torqur converter on to a lock up trans as in to a non lock up, the lock up system eats room inside the converter and they usually have less torque mulitpilication. But finding a lock up BB transmission may not be very evident anyway. Also, the input shaft is weaker because it's hollow.

[dwc43]

One way to tell if it is a lock up or not all you have to do is look at the converter hub. If both pump drive notches are the same it's a non lock up and if one notch is larger than the other it's a lock up converter. They did this so you would not put the wrong converter in the wrong tranny.

[rumblefish360]

Since you can get most anything for a lock up these days, there very good to use in your performance car. Nothing wrong with them. Full boggie race is another story. From what I'm told.

[cutting torch]

Originally Posted by dwc43

One way to tell if it is a lock up or not all you have to do is look at the converter hub. If both pump drive notches are the same it's a non lock up and if one notch is larger than the other it's a lock up converter. They did this so you would not put the wrong converter in the wrong tranny.

I just looked at one of each that I have, and they both have two identical slots for the pump. I do know that the lockup has a 23 spline input shaft, and the non-lockup has 24.

torch