VP converter- Trans visual ID guide

Discussion in 'The "Juice Box"' started by Jim Weise, Dec 19, 2007.

  1. Jim Weise

    Jim Weise 1000+HP

    Hi Folks,

    I just had a guy ship me what he thought was a VP converter.. delt with him before, and I am sure it's just an honest mistake, but it made me realize that we don't have a visual ID Thread for the Variable Pitch pumps and converters on the board here.

    So I took some pics..

    Fixed Pitch Converter T-400 Stator shaft (part of the front pump) VS. Variable pitch

    Here's the Fixed pitch stator shaft:



    Variable Pitch Shaft..



    Converters - Fixed Pitch VS Variable Pitch

    Fixed Pitch- When you look down the hub, all you see is the Stator splines.



    Variable Pitch- Looking down the hub, you see two bushings with a space in between, and then the stator splines. This is true of both the 12" and 13" VP converters, and no other converter will look like this.. This is positive ID!


    12" VS 13" VP converter ID





    12 "


    Close up of the 12" measurement..


    Visual ID- Converter Cover

    The 13" converter will have recesses to mount up to 6 mounting lugs-



    The 12" unit has provisions to mount only 3 lugs


    Now you can Field ID both the VP trans pump and converter, as well as tell the difference between a 12" and 13" VP converter.

    For you junkyard hounds.. print this out and throw it in your toolbox.. I actively purchase any 12" unmolested VP converter I can find. I pay $75, provide the box and pay for shipping, for a good 12" core (can't be a Poston (PAE)) unit, this offer only applies to a stock, untouched core. These cores are located in ST-300 two speed transmissions, in various 64-67 GM A bodies. I have also found them just laying in a "converter pile" in a junkyard in the past.

    I will ship you a box, plug and return lable along with a check for a good 12" VP converter.. all you have to do is take out your check, plug the converter and stick the Shipping paid lable on the box, and take it to a UPS shipper.


    Last edited by a moderator: Oct 17, 2009
  2. 6D9

    6D9 Well-Known Member

    Thanks Jim for the info.....Do you have any in stock right now if someone wanted to order one of your 1800/3200's???
  3. Jim Weise

    Jim Weise 1000+HP

    None in stock, I am out of cores right now..

  4. rex362

    rex362 paint clear and drive

    any good from a 2 spd getaway trans 1969 olds ?
  5. jamhdit

    jamhdit Just nuts about buick's


    Im Ready To Order One Of Your Switch Pitch Level Two Transmisions. So I Hope You Get Some Torque Converters In And Hope You Have A Nailhead Core?

    Also Sent A Email To Your Store


    GSXMEN Got Jesus?

    Jim - You might also post pics showing the spot welds on the SP converters, compared to the regular ones.

    You can make some of it out on your converter ID pics....maybe just zoom out to show more of it.
  7. Silver Bullet

    Silver Bullet Well-Known Member

    Thank you for the pics and info. I was able to verify my project motor & trans does have a SP just like my Riviera. Thats very good news.

    I have the creeping problem at traffic lights in my Rivi and found great info from you guys. Thank you. So my question is one I haven't seen.

    Does the switch pitch also function in reverse? My Rivi engages a little harder in reverse than drive. Is this correct, or should it be the same?
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Since reverse has nothing to do with the converter, I would say yes. You should be in high stall at stoplights. There is a switch up near the firewall that should put the converter in high stall at closed throttle. Reverse is 2.08:1 vs. 2.48 for 1st gear forward. That and the fact that you are probably in low stall (if it is creeping) would make reverse engagement harsher.
  9. Silver Bullet

    Silver Bullet Well-Known Member

    I keep hearing that one of the old tricks was to wire in a manual switch for the SP. Higher stall at take off puts you more into your power band, but how is this any different than WOT (assuming the SP is working correctly)? Is this to keep it in the high stall thru the shift points?
    I understand the how to on the 12v side, but is there really any advantage to this?
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The original SP valve bodies had specific calibrations to work along with the 2 stall speeds. The way the SP worked was high stall was used at idle (to reduce creep), and at over 60% throttle. Low stall occurred off idle and part throttle for better efficiency. The valve body got you into high gear sooner, and would not kick down until you applied full throttle (or close to it). Buick intended the car to accelerate at higher throttle openings using high stall instead of a forced down shift. The SP valve body has no 3-2 valve.

    At the drag strip, you only need high stall to launch the car. Shutting the converter off about 100' out provides the best E.T. and trap speeds. High stall at idle tames the rougher idle of a big cam. The valve body calibrations can be solved by a swap to the later valve bodies. If you try to set up your governor to shift higher automatically, you will find that the 2-3 shift will occur too early relative to the 1-2 shift. Swapping in a later valve body with a 3-2 valve gives you a part throttle kick down as well as a higher RPM 2-3 WOT shift point.

    I have a SP controller box that I bought from Poston Enterprises years ago. It is a timer box with an L.E.D. readout. The timer is adjustable between 0 and 11 seconds in .1 second increments. There are 4 connections, 12V, Ground, brake light switch, and transmission. The way it works, is any time your foot is on the brake, the converter is in high stall. When you release the brake, the timer counts down to 0 and shuts off the converter. At the track, I leave it at 3 seconds. This allows me to foot brake the car and launch, and use low stall for the balance of the run. On the street, I set it for 0 seconds. The high stall lets the engine idle easier and smoother. The timer box also has a manual mode to let you select stall speed directly. I have one of Jim's 12" ST300 modified converters. High stall is 3000-3200 RPM, and low stall is about 1800. The engine is very responsive even in low stall. Much better than the Stock 13" converter which had maybe 2100/1100 stalls. Hope that answers your question. There is more to read here:

    Last edited: Jan 22, 2008
  11. wkillgs

    wkillgs Gold Level Contributor

    V6 Switch Pitch converters

    Anyone using a V6 switch pitch converter on a BBB V8?
    I just bought one, and was surprised to see it is also 12.5" O.D.
    Are there internal differences that will give it a higher stall than the ST300 converter now in my '66 GS? I'm presently getting 2000/3000 stall from that one.
    Also, would there be any durability issues with using a V6 converter, or would the only side effect be higher fluid temp from more slippage (if that)?
    I'm wondering if I should have JW rebuild it before I give it a try.....
  12. Topless64-455

    Topless64-455 Well-Known Member

    I know JW would perfer the V6 SP TQ for a performance build.
  13. 65specialconver

    65specialconver kennedy-bell MIA

    Is the "BB"t-400 from 67 GS 400 a S/P? It sure shifted nice & hard ,chirp the tires on the 1-2 shift hard.:Brow: I'm trying to decide on rebuilding it or the T-400 S/P out of a "400"package 66 lesabre.Both have the original converters,but not at my disposal to look at right now.300 miles away:rant:
  14. DaWildcat

    DaWildcat Platinum Level Contributor

    I don't see a "BB" code for '67...the GS would've gotten a "BA" that year. Both the '66 & '67 would be variable pitch-equipped, the major difference being the nailhead vs. BOP bellhousings, respectively.

  15. wkillgs

    wkillgs Gold Level Contributor

    Re: V6 Switch Pitch converters

    Sooooo...is the V6 converter the same size as a sbb 12" unit?
    Do internal differences give it a higher stall?
  16. Re: V6 Switch Pitch converters

    I compared a known V6 converter to a known st300 converter today and there is slight visual differences. also the V6 converter is 8 lbs lighter than a st300 converter. the V6 weighed 35 lbs and the st300 weighed 43 lbs. both are the same diameter.
  17. Walt
    I looked at an old GM master parts catalog today and there were 3 different 12.5" VP converters. 64-67 V6, 64-67 skylark st300 and 65, 66 and 67 skylark Gransports. 3 different part numbers. hope this helps. Bob
  18. Larry J

    Larry J Stuck on Buick

    Re: V6 Switch Pitch converters

    Don't know if you guys have thought about a more modern approach. Lockup convertors in the TH700, and 4L80E transmissions are much more effective than the old SP TH400. They both have an overdrive, and the TH700 also has a much lower first gear ratio. The 4L80E is used in newer trucks and is heavier duty, like a TH400 with OD and Lockup.
    The only drawbacks for the 4L80E is you have to use a computer and sensors to shift it, and the price. The TH700 has only electronics for Lockup, and is an easier swap, as the 4L80E is a big unit.
    Just thought you'd like to hear that from a 20 year SP400 user (gave up on them when I went with a trans brake). Give your local ATRA Trans guy a call, and tell them Larry J from Westshore Trans sent you.

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  19. DaWildcat

    DaWildcat Platinum Level Contributor

    Yep, there are tons of people on the board that have overdrive swaps...a quick search will show you lots of conversations. We have some folks using aftermarket overdrive/underdrive units as well.

    Call me old fashioned, but I love being able to flash over 3200 on the switch and putz around town in low stall all day long. Can't say a high stall converter w/lockup can do that for me; I suppose it depends on the quality of the converter as to how much part throttle slippage you'd get while cruising.

    My converter's stator reacts so quickly between high & low it'll squeak the tires when I let off the switch at part throttle. Following immediately with a screech between 1-2 gets some strange looks and lots of questions from passengers. Usually it's a "what just happened?"

    I suppose it's a novelty.

    Last edited: Mar 30, 2010
  20. sootie007

    sootie007 65 Skylark -455 - T350

    Jim I have one for you with the deal you mentioned ..heres a few pics ..send me a box ...its out of my 65 lark- st300 with 79k miles on it....ps make sure you send me a plug as the one in the photo is for another converter I have ....thanks John Kennedy

    Attached Files:

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