Part Throttle Kick Down which type to use ?

[rustytoolss]

Been looking into the TPKD systems, there are 2 different styles (early 70 and back--and late 71 and up). Just wanting to ask which is better for a street cruiser/ driver (with a 2 barrel carb and 3.23 gears if that matters) Is there much difference between the two designs ?

 

[Dave6T4]

Chrysler made major modifications to the valve body casting to accommodate the PTK feature for '71 and up. Pieces are not adaptable to earlier valve bodies. These valve bodies used to be fairly easy to find in a junk yard's trashed transmission pile. I currently have one in my 1967 R/T with 440 and 3.23 gears, and like it. I believe the earlier style is adaptable to early valve bodies by drilling an oil passage hole in the VB. This kit used to be sold through Mopar Performance catalogue many years ago. I have no experience with this style, so cannot speak to its performance.

 

[Don67Satellite]

 

[rustytoolss]

Chrysler made major modifications to the valve body casting to accommodate the PTK feature for '71 and up. Pieces are not adaptable to earlier valve bodies. These valve bodies used to be fairly easy to find in a junk yard's trashed transmission pile. I currently have one in my 1967 R/T with 440 and 3.23 gears, and like it. I believe the earlier style is adaptable to early valve bodies by drilling an oil passage hole in the VB. This kit used to be sold through Mopar Performance catalogue many years ago. I have no experience with this style, so cannot speak to its performance.

so what year VB do you have ? and is your PTKD the early of late type ?

 

[qkcuda]

I grabbed a 73 transmission core for my 400 build, just so I could get the part throttle kickdown.

 

[Outsider]

Though not an expert on this subject, as I rely on Pat Blais, and he has said that the post '70 VBs are the preferred upgrade on street applications for all Torqueflites.

 

[turbine68rt]

Prior to '71 727's were non-ptkd.

 

[68 Sport Satellite]

for an expert opinion, give John Cope of Cope Racing a call. He'll probably have the correct valve body to sell you for this. He built my street/strip 727 with partial kickdown (although last I heard he doesn't sell full transmissions any longer).

 

[Cop car wagon]

Pat Blais, the quiet master. Rebuilt more Torqueflite's than the next top 5 rebuilders combined.

Though not an expert on this subject, as I rely on Pat Blais, and he has said that the post '70 VBs are the preferred upgrade on street applications for all Torqueflites.

 

[Dave6T4]

so what year VB do you have ? and is your PTKD the early of late type ?

I have the later style. Not sure what exact year I have. As I said on my post, I have no experience with the early style.

 

[oldkimmer]

I have the later style. Not sure what exact year I have. As I said on my post, I have no experience with the early style.

1971 up should have ptkd. On the bottom of the vb it has the year on it right under the accumulator. So a 1970 vb will be in a 71 vehicle. Kim

 

[Outsider]

Pat Blais, the quiet master. Rebuilt more Torqueflite's than the next top 5 rebuilders combined.

Ya Pat bought a '63 new and raced it while he was still in the Coast Guard, after he got out, he started building TFs. Been doing them for over 55 years, I met him about 45 years ago, though I was a 4spd racer.

Through the years I had him do some street car TFs for me, and now in our later years, and my last effort to go racing again after many years away, I'm racing his TFs for the first time. Back in '70s he supplied many, if not the most of west coast, and some back east, SS, Stock and serious bracket racers their TF trans.

I had him put a Cope VB in this year's trans so I could try the low band engagement which requires the lower half of VB to be machined new from a billet, which Pat never got to, as he relied mostly on factory parts to build his VBs.

Back the original poster, if you set it up right and put the part throttle KD VB in your TF, you will like it in your performance street car.

 

[rustytoolss]

Prior to '71 727's were non-ptkd.

I have seen copies of the early simple units used on slant six cars in 67 ( copies are sold by A&A Transmisions)

 

[rustytoolss]

1971 up should have ptkd. On the bottom of the vb it has the year on it right under the accumulator. So a 1970 vb will be in a 71 vehicle. Kim

Is that how the production dates work (70 on VB would be used in the 1971 model year vehicle ? )

 

[oldkimmer]

On most but not all as some were built into the following year. Kim

 

[turbine68rt]

I have seen copies of the early simple units used on slant six cars in 67 ( copies are sold by A&A Transmisions)

Correct, some of the early 904's had ptkd, unlike the aforementioned 727's.

 

[Dave6T4]

Correct, some of the early 904's had ptkd, unlike the aforementioned 727's.

904 VB is interchangeable onto a 727 by slotting a couple of holes in the steel separator plate. This can be done without taking the VB apart.The hole is already elongated on the aluminium bottom channel plate. Just modify hole in separator plate to match this, and you are good to go.

 

[rustytoolss]

So from everything I'm reading here..nobody has used the early type/A&A unit, and does not know how it reacts.

 

[oldkimmer]

I believe some members on FABO have used the one A&A sells. Kim

 

[AndyOpi66]

So from everything I'm reading here..nobody has used the early type/A&A unit, and does not know how it reacts.

Rusty,

I used the A&A one and it works ok. My valve body is a stock unit from 69'. It is hard for me to give you a solid recommendation as I haven't put that many miles on the car yet and I have highway gears in the back (2.94), so the opportunity for part throttle downshifts doesn't happen as often, but it was an easy install and seems to work, so hope this helps!

You will also find more on this topic on the c body forum. I found a couple of threads on there where guys raved about the A&A unit which is why I purchased.