Rochester 2bbl to Holley 4bbl on a 72 350

Discussion in 'Small Block Tech' started by JoRion, Jan 20, 2021.

  1. JoRion

    JoRion Member

    Hey all,

    I recently was given a Holley 4bbl. Currently have a rochester 2gv on the 350. What options do I have for intake manifolds? Is TA performance the only route?
     
  2. LARRY70GS

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

    Yes, TA Performance is the only option with their two 350 intakes. A Holley carburetor won't bolt on to a stock intake without an adapter. You can get the adapter if you can purchase a stock 4bbl intake.
     
  3. No Lift

    No Lift Platinum Level Contributor

    What is the model # of the carb? On a stocker it probably can't be too small but it easily could be too large.
     
  4. alec296

    alec296 i need another buick

    Ta is out of stock on the stage 1 intake currently. I would not suggest a vacuum secondary Holley and 600 is kinda small. You may need a 4 barrel accelerator cable also. I would work on some other mods while you look for a manifold. Like a torque converter and a distributor recurve kit. Along with Larry’s write up about timing the engine
    https://www.v8buick.com/index.php?threads/power-timing-your-buick-v8.63475/
     
  5. pbr400

    pbr400 68GS400

    If the car is mostly stock, sell the Holley and buy a quadrajet and matching manifold.
    Patrick
     
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  6. nekkidhillbilly

    nekkidhillbilly post whore

    they ran an adapter on my car to run edlebrock. it runs pretty well.
     
  7. DEADMANSCURVE

    DEADMANSCURVE my first word : truck

    adapter , they claim a loss of 50-100 cfm . if you do decide to use one use a 4-hole style .
    let us have the holley list# from the front of the choke tower .
    I have no problem running vac sec carbs on my 360 , truthfully I've tried dbl pump carbs and they just don't feel quite as responsive off cruise . #3310's (750) really seem best overall so far . the DP carbs are good up top . the 600's are a little "small air" feeling . 650 AVS good . I was curious how a 650DP would work .
     
  8. Fox's Den

    Fox's Den 27 years of racing the same 355 Buick motor

    I used a 650 Dbl pump spread bore which would fit the stock intake and ran decent. Would smoke the daylights out of that right rear with my 2;56 gear.

    A 650 4bbl carb on a stock engine would be good off idle with the response. A 750 is best. A Q-Jet is a 750

    The Q-Jet will work best with the stock intake so worth looking for one or get one rebuilt from one of our great builders here. Especially if you plan on using a stock intake Put a 1" adapter under it and that may make a little more power.

    The adapter is not worth a crap with a square bore like Holley it just does not work even the Edelbrock on stock intake.

    I ran a Carter AFB on a stock intake to try and it did not work worth a crap I did all kinds of jet chances and rod changes rear spring on secondary, it just would not run right at off idle cruising.

    I put the Q-Jet back on.

    A TA intake is different, you can use any carb that trips your trigger.
     
    JoRion likes this.
  9. nekkidhillbilly

    nekkidhillbilly post whore

    mine is a open center one
     
  10. JoRion

    JoRion Member

    Hey all,

    Got a chance to look at the carb. It is stamped 80555-1. After looking up the number, looks like the carb is direct swap for a quadrajet. Is that correct?
     
  11. JoRion

    JoRion Member


    Very good points. I've put a TA distributor in it. Also did a 4 speed swap. Currently trying to track down other issues such as blower motor, and an intermittent problem with the dash lights. The stock carb has been working great for my purposes. Would just be a fun project in the long run and a nice upgrade.
     
  12. LARRY70GS

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

    It's a spread bore carburetor but 650 CFM. That is smaller than the 750 CFM Q-jet.
     
  13. No Lift

    No Lift Platinum Level Contributor

    A low compression stock cammed 350 won't support anything over 5000 rpm. You'll never notice the 100 cfm difference. With the 4 speed you may be able to change the seconday spring to open them up faster. In this case you could use a stock intake manifold and that carb should bolt right up. The problem is to get your hands on even one of those. There are idiots on E-Bay that want $150 for iron 2-bbl intakes which is crazy. They aren't worth the price to ship them. If you can't get a stock intake hold out for the TA dual plane Stage 1.
     
  14. JoRion

    JoRion Member

    Are you saying that the 100 cfm difference between the holley and the quadrajet won't be noticeable? The holley will be a definite step up from the current 2 barrel setup though, correct?

    I also hear what you're saying about the manifold. I do see some pop up on craigslist from time to time. What year 350 4bbl manifolds will bolt up to the 72 engine?

    As for everyone's comments on the quadrajet, it is definitely worth considering. My thought process was: I got a free Holley carb. I'm sure that is an improvement over the 2bbl that came bolted on the engine. Seems like an easy upgrade – especially given that it is a free carb.
     
  15. buickbill

    buickbill Well-Known Member

    i thought the main advantage of ta was weight saving and the stock 4v iron flowed almost as good ?
     
  16. No Lift

    No Lift Platinum Level Contributor

    Yes. Yes. As long as it is in nice shape, yes it is a good upgrade.
     
  17. Mark Demko

    Mark Demko Well-Known Member

    Where are you located Bill?
    I have the stock iron 4 bbl intake from my '71 350 GS I'd be willing to part with.
     
  18. DEADMANSCURVE

    DEADMANSCURVE my first word : truck

    had a 80555 on my 360 , actually really liked it . a little fuggly so i adapted dual feed bowls for it . someone else on here ran one on a 455 i think . said it was ok runner .
    mike is correct - do your home work on vac sec spring selection . that is probably a "plain" spring originally . purple ( recommended ) or yellow are the next step quicker springs .
    edit : in case you decide to redo the 80555 i checked specs for it - needle n seats - #510 ( .110 non adjustable style ) , front jets - #62 , rear plate - #54 , power valve - 6.5 , nozzle - 40 , vac sec spring - yellow ( surprise , not plain ) . cheapest kit i've found is the quick fuel #3-206 i think it is . seems to work fine . no plunger under nozzle , check ball in metering block passageway instead . standard holley metering blocks are incorrect . pump shot holes are dif also .
     
    Last edited: Jan 25, 2021
  19. alec296

    alec296 i need another buick

    The Holley will only be better with proper jetting and other carb settings. I would suggest looking at other tweaks while you look for intake. ,a distributer recurve kit, torque converter,rear gears, even a 275 first gear for transmission if it’s still automatic. You can dive into engine and do porting and mill heads with a torque cam like the level 3 crower or the 284-88 from ta. Advanced 4 degrees when degreed in, for lower compression engines. Either should work well with the 2 barrel in my opinion
     
  20. hugger

    hugger Well-Known Member

    I have a 72 4bl intake you can have
     
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