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727 Valve Body

Posted By: 426lloyd

727 Valve Body - 05/11/21 11:40 AM

Converting a 1978 lockup 727 to a non lockup , will a 1971 valve body work ok , thanks
Posted By: A727Tflite

Re: 727 Valve Body - 05/11/21 01:12 PM

When you mean converting it, you simply do not want lockup. That’s it?
Posted By: 426lloyd

Re: 727 Valve Body - 05/11/21 03:11 PM

Correct , just wanting to know if a 71 vb. will work with the 78 case that had the lockup vb .
Posted By: A727Tflite

Re: 727 Valve Body - 05/11/21 03:51 PM

Originally Posted by 426lloyd
Correct , just wanting to know if a 71 vb. will work with the 78 case that had the lockup vb .


If you want to disable lockup just block the lockup valve. No need to switch valves bodies. On the 78 there is a lockup module with an aluminum tube running to it.
Just block the valve by replacing the spring inside with a plug.
Posted By: Locomotion

Re: 727 Valve Body - 05/11/21 04:13 PM

But I believe you can't use a standard converter unless you switch the pump/input shaft. Different splines?
Posted By: 426lloyd

Re: 727 Valve Body - 05/11/21 04:19 PM

Ok , that's what I've done , changed all that for non lockup , that is why I'm asking if the 71 vb will work with the 78 case.
Posted By: 426lloyd

Re: 727 Valve Body - 05/13/21 01:51 PM

Anyone might know?
Posted By: scratchnfotraction

Re: 727 Valve Body - 05/13/21 02:29 PM

IIRC yes the 71vb will fit the 78 727 as you have converted the spline/TC to non lock up.

IIRC the 71 VB will NOT have a PTK valve. you can use a housing/spring/valve from a /6 904 trans on the 71 VB for a PTK. (IIRC this is what I did for my 67-727 for PTK)

IIRC the 78 VB would have PTK with a downshift limiter built into it.

904 and 727 lock up trans I have had, I blocked the valve and order up a fresh lock-up TC with out the clutch ring/guts in the TC and use the non-lock up spline/shafts to save on teardown and parts.

but then again I have broke and killed more than I have ever been able to fix so hopefully someone will confirm for sure 100% + for you.

I have a good 78-727 VB on the parts shelf if you would prefer to use a 78 VB in the 78 case. PM me if you are interested.
Posted By: A727Tflite

Re: 727 Valve Body - 05/13/21 05:02 PM

Originally Posted by 426lloyd
Anyone might know?


I answered your question earlier. Why do you want to install a different valve body ?

Because you have a shift kit for that year or another reason?

If you want to disable lockup, just block the l/u valve in the module. The module is the aluminum unit with the aluminum tube running to it.
Posted By: 426lloyd

Re: 727 Valve Body - 05/13/21 05:19 PM

Maybe I didn't explain it enough , l do not want a lockup 727 , I have non lockup stahl converter I want to use , changed the components for non lockup , and have a 1971 vb I wanted to use and was not sure if it would work in the 1978 case . I want to save the lockup vb for another time and the other parts . I thank you for the reply .
Posted By: John_Kunkel

Re: 727 Valve Body - 05/13/21 06:08 PM

If you have replaced the front pump assembly, input shaft and rear clutch piston retainer to pre-'78 non-lockup parts (or '78-later non-lockup parts), then, yes you can use the '71 VB. The factory has stated that the lock-up case can be used for "prior model service".
Posted By: 426lloyd

Re: 727 Valve Body - 05/13/21 07:55 PM

Thank you
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