Register now to get rid of these ads!

Technical Chevrolet aluminum intake / Rochester 4GC question

Discussion in 'Traditional Hot Rods' started by Steffen Jobst, Sep 19, 2016.

  1. Steffen Jobst
    Joined: Sep 16, 2016
    Posts: 1,996

    Steffen Jobst
    Member

    Hello from Germany. --> About me

    chevy intakes liste.png

    Can anyone tell me the differences between these 5 intakes?
    I want to use them on a 327 Chevy Engine.Wich Intake would be the better choice?
    ----
    I want to use a Rochester 4GC carb.
    Are there different carb models and wich one would be the best?
    Are they available with manual choke?
     
    Last edited: Sep 19, 2016
  2. I'm not going to claim to be an expert on the intakes, but I will give you my 2c. You may already know this but, the Corvette intakes (62 and 63) are going to be low rise because of the lower hood. The later intakes were under taller hoods, so a hi rise was used. This would give you more top end HP on the 327. Some of the intakes may also have incorporated vacuum ports for power brakes and the like and thus a different part number. Other than that, they are the same. I believe the 4GC came in one CFM and the bases are the same size. So anyone you find will bolt on. I don't think you will find a manual choke.

    Do you have all these intakes, or are you trying to find the right one for your application?
     
  3. Steffen Jobst
    Joined: Sep 16, 2016
    Posts: 1,996

    Steffen Jobst
    Member

    Good infos. Thanks you.
    I don't have a manifold yet.
    I want to collect some information before I start sesrching & buying one.
     
  4. tb33anda3rd
    Joined: Oct 8, 2010
    Posts: 14,772

    tb33anda3rd
    ALLIANCE MEMBER
    1. Connecticut HAMB'ers

    i always thought the 4gc carb had four small holes. the intake picture shows two large, two small holes. i think you would need an adapter.
     
    Register now to get rid of these ads!

  5. ididntdoit1960
    Joined: Dec 13, 2011
    Posts: 825

    ididntdoit1960
    Member
    from Western MA

    Those are all very expensive intakes (especially the '62 one) and are all high rise and flanged for an AFB or Holley carb - you would need an adapter to run a 4jet - I would either get a different intake (cast iron for a wcfb or 4jet - paint it with aluminum paint if you want that look - aluminum small flange manifolds are rare - may have been used in industrial and marine applications) or step up to an afb/holley
     
    Steffen Jobst likes this.
  6. The 4GC did come with a manual choke (I know I have two of them on my Pontiac 400) mine are 1958's but I do not know the application. 2X,^ you will need an adapter, all of these are either Holley, Quadrajet patterns. The 4GC uses an almost square pattern with 4 almost same size holes.
     
    Steffen Jobst likes this.
  7. carbking
    Joined: Dec 20, 2008
    Posts: 2,476

    carbking
    Member

    The Rochester 4G series carb came in several different sizes from roughly 400 ~650 CFM.

    The Rochester 4G series carb came in three different throttle body designs:
    (1) The old "square" 3 3/4 x 3 7/8 bolt pattern
    (2) The newer "Carter" pattern with equal size bores
    (3) The "Carter" pattern with the secondaries slightly larger than the primaries

    Some of the Rochester 4G series came from the factory with manual choke.

    No help on the manifold question, not my area.

    Jon.
     
    Rex_A_Lott likes this.
  8. Steffen Jobst
    Joined: Sep 16, 2016
    Posts: 1,996

    Steffen Jobst
    Member

    Thank you, Mr. Carbking.
    Any advice where i should start to search?
     
  9. porknbeaner
    Joined: Sep 12, 2003
    Posts: 40,959

    porknbeaner
    Member

    All the intakes that are not designated holley would have come from the factory with a Carter carb mounted to them. Your intake and car choice would be based on the rest of the build, as well was the intended use for the car in question.

    Something to think about when considering Corvette is that they were not "Glass Strippers" (dragsters). As glass cars go that were not as light as one would imagine, ('62 tipped the scales @3100 lbs) and their intended use was as a road car. So a stock set up would have been with mid range to top end in mind. Tat is no reason to not use a 'vette intake, just something to think about.
     
    lothiandon1940 likes this.
  10. carbking
    Joined: Dec 20, 2008
    Posts: 2,476

    carbking
    Member

    Steffen - you need to narrow your search.

    If you have decided on your engine build (displacement, camshaft, compression ratio, etc), then you can determine the SIZE of the carburetor required for your engine:

    http://www.thecarburetorshop.com/Carburetorsizeselection.htm

    Once you have this determination, you can then determine which, if any, Rochester 4G series carbs (your choice) fit that determination; and look for one.

    Also, once you have determined the carburetor you wish to acquire, then you can determine which intake manifolds are compatible with that carburetor:

    http://www.thecarburetorshop.com/Four_barrel_mounting_flanges.htm

    Everything has to be compatible with each other.

    Incidentally, I applaud your choice of the Rochester 4G. These are excellent carburetors, both technically and in reliability. Plus, many think they only came as a 400 CFM, so they have the advantage of "stealth". We used to sell lots of the 625/650's to the street cheaters that put 350's in the older Chevvies and called them 265/283's. That market has died off somewhat, as now many are into big blocks, and no one cares.

    Jon.
     
    Last edited: Sep 19, 2016
  11. Steffen Jobst
    Joined: Sep 16, 2016
    Posts: 1,996

    Steffen Jobst
    Member

    Thanks.
    I know. I just wanted to know if it generally would fit.
    When I have the engine data, I will narrow my search.
     
    Last edited: Sep 19, 2016
  12. aerorocket
    Joined: Oct 25, 2007
    Posts: 488

    aerorocket
    Member
    from N.E. P.A.

    The 63 manifold (3794129) has a 4 1/4x 5 5/8 bolt pattern. The 64-5 manifold (3844461) has a 5 1/4x 5 5/8 bolt pattern. Some large 4gc carbs will fit the 63 manifold such as one from a 63 394 olds. They are all high rise manifolds.
     
    Steffen Jobst likes this.
  13. Steffen Jobst
    Joined: Sep 16, 2016
    Posts: 1,996

    Steffen Jobst
    Member

    Thank you. Good info.
     
  14. carbking
    Joined: Dec 20, 2008
    Posts: 2,476

    carbking
    Member

    Steffen Jobst likes this.
  15. The '62 and '63 manifolds used Carter AFB carbs. Some 4G carbs will fit the "Carter" bolt pattern. The '64 through '67 manifolds used Holley carbs. No 4G carbs will directly fit the "Holley" bolt pattern. All of the manifolds listed are quite dear to Corvette restorers. Better aftermarket manifolds can be found which will be much less expensive.
     
    Steffen Jobst likes this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.