Buick 350 aluminum intakes

Discussion in 'Small Block Tech' started by peterjack, Jul 3, 2017.

  1. peterjack

    peterjack New Member

    My stock 350 intake is leaking. I'll be darn-didly-arned if I'm gonna put that big cast iron beast back on. I'm gonna put an add in the parts wanted section for one soon. So which one do I want? Anyone bolt one on with positve results? Poston????? T/A?????
     
  2. Mark Demko

    Mark Demko Well-Known Member

    If you go aluminum, go TA Stage1 Dual Plane.
    Whats leaking on your stock one?
     
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  3. alec296

    alec296 i need another buick

    TA stage 1 is better then the Poston. But both are scarce. And both require a different choke setup. Everyday performance has an electric conversion kit.
     
  4. sean Buick 76

    sean Buick 76 Buick Nut

    There are some issues with the Poston intakes, I would buy a TA intake...
     
  5. 72gs4spd

    72gs4spd Well-Known Member

    Just out of curiosity what are the issues with Poston intakes?
     
  6. alec296

    alec296 i need another buick

    They tryed to split the engine so both sides are a mirror of each other on the same plane or level. So it feeds 1 cylinder on one side and 3 on the other. It seems to work better with a spacer on it. Like it needs more velocity or something.
     
  7. alec296

    alec296 i need another buick

    Someone had dyno tests of the 3 intakes years ago . Showed gains or losses.
     
  8. sean Buick 76

    sean Buick 76 Buick Nut

    Number 3 cylinder was super lean with the Poston intake. It has a major flaw and it went into mass production knowing about the flaw. I would never use a Poston intake it may be a loss vs a stock intake.

    The TA dual plane intake while slightly better than stock is not a major gain as it also has poor air fuel distribution and may cause lean cylinders.
     
  9. wovenweb

    wovenweb Platinum Level Contributor

    Easy answer, have the intake flow balanced. That was done to the one I purchased along with some Greg Gessler ported 350 heads.
     
  10. Just wondering if there has been any more Dyno or ET results with the TA SP3 intake? I've only read one article which mainly tested a track only car. Any street results?
     
  11. Mark Demko

    Mark Demko Well-Known Member

    I ran the SP3 on the street and track, tho my combo wasn't optimized for the SP3 at the track, and my trans. started going away so I never got any concrete numbers as far as the track goes.
    On the street its fine, drivability is awesome for a single plane, didn't feel any loss of low end torque compared to the the Stage 1 DP.
    The Q-Jet doesn't seem to like a single plane when yah floor it, only because of the lack of an accelerator pump on the secondary side. A double pumper solved that;)
    Stay with the stock iron 4bbl, or TA Stage 1 intake (dual plane) for street and most track duty.
    The few of us that do have an SP3 are still figuring it out, and your combo HAS to be built around the intentions of this intake.
    An SP3 will not add anything to a stock or mild build.
     
  12. Thanks Mark for the feedback. It's hard to get good info on these newer products, so I'm glad there's a few guys out there testing them so the rest of us aren't left guessing. Happy to at least have options now.
     
  13. Mark Demko

    Mark Demko Well-Known Member

    Your welcome, hope this info helps.
    The SP3 will complement the aluminum heads when they become available.
    The Stage 1 DP is still the best aluminum intake for stock or a mild build.
     
  14. Gary Farmer

    Gary Farmer "The Paradigm Shifter"

    Here's my take on the Poston intake.

    The Poston intakes were both (they made one for the Buick 350 and the Buick 400/430/455) coined the "S" divider intakes, which was inherently a low profile single plane intake with a center divider to separate cylinders that fired too close to each other (#5 and #7). The idea was to get the best of both worlds (between a single and dual plane intake), but fell short of expectations.

    The main reason for this is that the plenum volume was too small, and so there was some starvation of some cylinders when the fuel/air charge had to move a greater distance after having moved to one side (a sort of 'back and forth' reversion inside the intake) due to the smaller plenum volume's inability to feed every cylinder effectively on each side of the "S" divider.

    This is also why much better performance can be obtained by either milling the center divider down some, or using a spacer (or both) that permits the fuel/air charge to move from one side to the other somewhat, so that one side can help the other out. This makes the "S" divider intake a sort of single plane-dual plane hybrid that really doesn't have the strengths of either intake, but rather the weaknesses.

    You can still get one to perform, just have to put the bandaid (milling center divider and/or using spacer) on it.

    The Edelbrock B4B intake for the Buick big block outperformed the Poston "S" divider intake by a pretty wide margin; which is to say, you will actually LOSE power by using one (in its untouched, out-of-box form) over the factory intake manifold.

    A dual plane intake has longer runners (opposite side of carb/intake feeding cylinders on the other side) and separates the cylinder feed by a 2-by-2 basis, splitting the fuel/air distribution more evenly, while the Poston "S" divider puts the runners too close from the carb to valve on a low-profile design, feeding 3 cylinders on one side then 1 cylinder on the other.

    This is NOT intended as an anti-Poston or pro-TA post, just stating the facts. The dyno and track results speak for themselves.

    Here's some literature regarding these intakes:

    PostonVSEdelbrockManifolds.jpg PostonSDivider2.jpg
     
    Last edited: Jul 11, 2017
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  15. Fox's Den

    Fox's Den 355Xrs

    This is all true, too bad though the company had a lot of other decent parts, they sold a lot of interior and exterior parts. They had their own cams and parts for Turbo cars. They had a little bit of everything for the Buicks.
     
    Gary Farmer likes this.
  16. Jclstrike

    Jclstrike Well-Known Member

    Ive been running the SP3 on my car and I have had no issues on the street with it. I went from the factory intake to the SP3. I feel that my mid to high range is much better with no difference in the low range but that could be due to the the manual tranny possibly. Another thing I noticed is that my motor is staying slightly cooler than it was prior to the install but I assume its just from going from cast to aluminum.
     
  17. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Not trying to Highjack the thread but I currently have a Poston Intake on my 70 skylark. I am guessing I should add a 1 inch spacer while i save up for a TA intake? Would the Poston still be bad if my engine is fairly stock? hmmm
     
  18. TrunkMonkey

    TrunkMonkey Well-Known Member

    I bought a 1968 Skylark and it has the Postin S divider and a Holley 600CFM square bore.
    Ran like a 2bbl car. So I pulled the square bore and put a 750 CFM Q-jet (Quadrajet Power), and it's a different car.

    I ordered a 1" spacer for the Q-Jet and will let folks know if it has (percieved) difference.

    Not to be a hater, but the best thing the Hollies ever did, was Long Cool Woman...
     
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  19. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    I'm curious as to how much of an improvement it will be. I currently have e a 650cfm or 750 edelbrock I need to double check the CFM. It is a squarebore. It seems to rub fine but I do intend to curve my timing. I will go with the spacer to see if I notice any difference
     
  20. alec296

    alec296 i need another buick

    I would Dump the Edelbrock carb. Runs lean mid and top . Put an air fuel meter on it and rejet carb. Intake does not really have impressive gains as there was a dyno test done on them years ago. The stock intake had best low end power, depending on cam and rest of combo.
    Really better off with a Quadrajet Power built carb.
    A Holley vacuum secondary carb isn’t that great of a choice either
     

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