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Part throttle downshift not available with 440 and 426

Posted By: STROKIE

Part throttle downshift not available with 440 and 426 - 07/30/13 12:32 AM

Just reading Shift Linkage Adjustment Guide, and I would like to know why Part throttle downshift was not available with 440 and 426 Hemi options...

Attached picture 7794785-Ptk.jpg
Posted By: lewtot184

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 02:11 AM

i don't think chrysler went to part throttle downshift until the early seventies. just put an early seventies valve body in it and your good to go.
Posted By: Supercuda

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 02:15 AM

part throttle downshift was done to compensate for lack of torque.

You think the 440 or Hemi had that problem?
Posted By: STROKIE

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 12:33 PM

Thanks...
I'm gone skip the idea to add a PTK on my 451cid.
Posted By: JohnRR

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 02:33 PM

Quote:

i don't think chrysler went to part throttle downshift until the early seventies. just put an early seventies valve body in it and your good to go.



This , I'm pretty sure PTK didn't show up till 1971 ...
Posted By: scratchnfotraction

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 03:08 PM

IMHO,with a 451 you will know when you need to manualy pull it to 2nd gear and shift back to 3rd.
Posted By: BigBlockMopar

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 03:28 PM

Quote:

part throttle downshift was done to compensate for lack of torque.

You think the 440 or Hemi had that problem?



Personally I find it very annoying when an engine keeps working against a transmission hanging in 3rd gear when doing 10-15 mph orso.
Posted By: Anonymous

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 03:39 PM

Even more annoying was driving a Hemi Charger back in the day and getting beaten by a small block from a 35 mph roll because your tranny won't go into low gear above 30 mph no matter what you do. Manual/automatic valve body fixed that.

Not sure what years had that problem, but I know the 67's and 68's did.
Posted By: John_Kunkel

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 06:58 PM

Quote:

This , I'm pretty sure PTK didn't show up till 1971 ...



'71 for the V8 but the /6 had it as far back as '67. The factory thinking was that the 440HP and Hemi were never geared as high as the standard performance models and didn't need PTK.

When the V8 PTK was introduced, the 440 and Hemi didn't get it but in later years the 440 did get it.
Posted By: dogdays

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 07:28 PM

And the valve bodies interchange, right? So a PTK body will fit in any Torqueflite, right? Making it easy to retrofit?

R.
Posted By: 70Duster440

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 08:59 PM

You can add a PTK "module" to your valve body of the same era. I've done it.
Posted By: JohnRR

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 09:18 PM

Quote:

You can add a PTK "module" to your valve body of the same era. I've done it.



Correct
Posted By: lewtot184

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 11:07 PM

Quote:

And the valve bodies interchange, right? So a PTK body will fit in any Torqueflite, right? Making it easy to retrofit?

R.

i've used PTK valve bodies in a '69 tranny with no issues.
Posted By: John_Kunkel

Re: Part throttle downshift not available with 440 and 426 - 07/30/13 11:30 PM

Quote:

And the valve bodies interchange, right? So a PTK body will fit in any Torqueflite, right? Making it easy to retrofit?



Nope, the VB has to be '67 or later. The earlier VB's lack the throttle pressure sense port.

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