350 2 barrel to 4 barrel swap

Discussion in 'Small Block Tech' started by Deacon07, Jan 27, 2013.

  1. Deacon07

    Deacon07 1969 Buick Skylark

    Hello again, I'm trying to collect all the parts and pieces to do my swap from a 69 skylark 2 barrel to a 4 barrel. Basically at this point I'm not sure if I need to get a different throttle bracket and throttle cable.

    I have the carb(I did rebuild it myself with the help of cliff ruggles book, but if I have any issues there, I have just myself to blame), manifold, manifold gasket, thermostat, temp sensor, pcv valve, pcv valve grommet (correct one was hard to find, parts store always recommended one that was too big) correct fuel line, new fuel pump (figured why not since I'm there) has the older choke set up on it, not sure if I should change out to electronic or not, also has the original choke pull of, maybe should replace that too, but those are things I can do after I get it all on there.

    Basically what I'm after, is, is there anything I'm missing? Do I need to get the straight throttle cable bracket as opposed to the 45 degree one, do I need a different throttle cable? If I do need those items, where can I get a hold of those things, I've kinda searched around and not sure there are repro one's available.

    I would like to take pictures of everything that I do so that I can document and possibly set up a how to, unless there is one that I can reference and I'm blind. (hoping)

    thanks for any help.
  2. Deacon07

    Deacon07 1969 Buick Skylark

    All done, 4 hour job. Was a lot easier than i thought. Easy 4 hour job. No bracket or throttle cable needed.

    Maybe a little fine tuning, but all in all seems to run well.
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Usually the cable/and or bracket are different. Make sure the carburetor is wide open when you floor the gas. Get someone to help you check.
  4. Ricardo Booker

    Ricardo Booker Well-Known Member


    Did you take any pic's? I want to do the same swap, having trouble finding a 4 Barrel intake around here.
  5. Deacon07

    Deacon07 1969 Buick Skylark

    Yeah i took pics, I'll try to get them straightened out and put together this weekend.
  6. techg8

    techg8 The BS GS

    FYI the 45 degree throttle cable bracket is correct for a four barrel setup

    The straight up one was the two barrel bracket.

    Like Larry said, be sure to check that the secondary throttle blades are wide open when the pedal is floored. More often than not, they wont be.

    another FYI is that you can bend the gas pedal bar to get some more throttle opening at WOT if you need to.
  7. Deacon07

    Deacon07 1969 Buick Skylark

    Ok, maybe i got them backwards. Anyways i checked the travel on the pedal along with the lever travel and its all the way open with with the pedal on the floor.
  8. Deacon07

    Deacon07 1969 Buick Skylark

    Parts I used
    Valley Pan Gasket and black rtv Silicone
    Rebuilt Carb
    4bbl Fuel Line
    PCV Valve
    Temp Sender unit
    4 bbl Air Breather

    1. Purchase valley pan gasket and tube of black rtv silicone.
    2. Remove air cleaner assembly and all hoses going to it.
    3. Place Pan under motor for coolant.
    4. Clamp off heater hose with vice grips and unhook.
    5. Remove hoses going to thermostat trying to get as much coolant into the pan as possible.
    6. Move the hoses out of the way as much as possible.


    7. Remove Fuel Line (buy a 4bbl fuel line as the port on carb faces forward not the side).
    8. Remove the large carb spring.
    9. Remove the carb linkage and brackets on manifold for the carb.
    10. Start loosening the 4 bolts per side on the manifold.
    11. Disconnect the trans line in the rear of the manifold.


    12. Hopefully with the help of a friend remove the manifold.
    13. Remove valley pan gasket.
    14. Place towels down and clean off all ports. (I used a 3M green pad)
    15. Place 2 rubber ends on with silicone on the corners.
    16. Put beads of silicone around ports on bottom of valley pan as instructed.
    17. Place valley pan down and hold in place for a bit (hopefully have a friend hold it down.
    18. Put new manifold with carb installed on and torque down.
    19. Start hooking all the hoses back up.
    20. Check all bolts to make sure everything is tight, especially the carb bolts.
    21. Hook up linkage and bracket, I had the 45 degree bracket so I did not need to get one.

    I also did not have to reinstall the piece bolted to the manifold and pushing against the throttle linkage, just the large spring. Shown in this picture.


    22. I installed a new sender unit, thermostat, pcv valve.
    23. Change the oil as some coolant or other material may have leaked down.
    24. Add coolant as needed to get back up to normal.
    25. Fire it up and check all your seals.

    Honestly I thought it was going to be quite difficult, but honestly if you have about 4 or 5 hours you should be fine.

    Also, it may be suggest to drain the coolant before you start so you don't have to deal with that. I just decided not to, and it is probably a better idea to drain it.

    I probably forgot a few things, so please ask if you have any questions.
  9. ronbz455

    ronbz455 Big Butz Racing

    I think my 4 barrel throttle braket was different than that.
    300sbb_overkill likes this.
  10. kevin taylor

    kevin taylor 69 Buick Builder

    Great post. I also want to change out the 2 barrel for a 4 barrel on my 1969 skylark 350-2. Anyone know if there is a problem putting a 1970 4 bbl manifold & carb on the 1969 engine?
  11. alec296

    alec296 i need another buick

    Should not be an issue, I do suggest a 4 barrel accelorater cable and the 69 distributer may be running off manifold vacuum and the 70 carb runs off ported vacuum. So retiming distributer or distributer replacement may be needed.
    But confirm if distributer is connected to manifold with 2 barrel.
  12. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    If you have the correct 69 distributor, it will have 30-34 * of mechanical advance and be initially timed at 0*(TDC). In that case, you’ll want manifold vacuum to the vacuum advance canister. The 1970 carburetor will have a manifold vacuum hook up, so you can connect it that way.

    Last edited: Dec 12, 2018
    alec296 likes this.
  13. JStov

    JStov Well-Known Member

    Hello im doing a 2brl to 4brl swap and in yhe process of puting it back together. I have a qeustion where does the transmission linkage get connected on the 4 brl setup? In my 2 brl there was a place to connect it into my 2 jet but i dont see one on my quadrajet plz help thanks in advance

    Attached Files:

  14. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    JStov likes this.
  15. JStov

    JStov Well-Known Member

    Yes THM350
  16. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    So it is a detent cable (kickdown). You can run without it. Earlier Buicks hooked it to the gas pedal.


    That is it, with the rod and adjustable clip. Not sure what the gas pedal looks like on a 76 Regal. Does it pivot on the firewall, or at the floor? See if that kit I linked can help. Contact Ken Gies (techg8, Everyday Performance)
  17. JStov

    JStov Well-Known Member

    Wow really I don’t have to connect it huh? Ok I’ll check with him thank Larry
  18. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    You won't have a kickdown, but it won't hurt the transmission. Not so with later transmissions that use a TV cable. You can smoke the trans if it isn't connected or adjusted wrong. Running without the detent cable can affect shift points and the kickdown as mentioned.
  19. buick64203

    buick64203 Just plum crazy Staff Member

    That must of been a mess! How much antifreeze went into the engine?
  20. JStov

    JStov Well-Known Member

    I just checked my gas paddle and no that cable is not hooked to it its defiantly routed down to the trans. I saw the post where this was discussed a few years ago lol I'll be contacting Ken here in a few thanks

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