Would this carb be too small on a 455?

Discussion in 'The Mixing shop.' started by 69SkylarkGS, Oct 12, 2019.

  1. 69SkylarkGS

    69SkylarkGS Well-Known Member

    F238F6B9-6B27-4B3F-992E-EA02F65C64C6.png 9D7F92D4-069B-4878-8499-A4C3F9252F27.png CDA3DD4D-DD4D-47CA-9258-6C131A1539C8.png 9EB657C9-49EC-4031-8F7C-509011D319BB.png A32242BB-30A3-420B-824F-587C1F489002.png This carb is currently sitting on a Chevy 350 (30 over) the previous owner put in my 69 gs. It’s an AED 750 HP. It functions fine but is too much carb for an iron headed Chevy 350 with a mild cam. The previous owner spent 600 plus on this carb alone. I’m debating trying to use it on my 455 that I’m eventually going to swap in. The 455 would be mildly built (mild cam, aluminum heads if budget allows or cleaned up small valve 70 heads, ta headers, 2 1/2 exhaust etc.). Short block is a low mileage 70 but will need to be balanced due to coming out of an automatic car and going into a manual car. My other options are a 70 q jet off this same low milage engine. It’s in great shape but sat for years so will need a rebuild. I also have a q jet from a 75 455 that will definitely need a rebuild.
  2. DasRottweiler

    DasRottweiler -BuickAddict-

    I'm thinking it would be a good carb for a sbb 350 , you are going to want an 850 or above for even a mildly built 455. I have a Demon 850 on mine and am debating moving to a bigger carb.
    My experience, others will vary.....JIM
  3. 69SkylarkGS

    69SkylarkGS Well-Known Member

    Thanks for the reply, if your 850 isn’t enough I’m definitely going to run out of steam with the 750 then. It’s a nice set up but it seems like it’s too much for the Chevy 350 and probably not enough for the 455.
  4. hugger

    hugger Well-Known Member

    It will be fine for street use,..it will actually be very crisp and responsive
    Mart, sailbrd and 69SkylarkGS like this.
  5. 69SkylarkGS

    69SkylarkGS Well-Known Member

    Thanks for your response, maybe I’ll give it a try when I get the engine together. I was hoping I could save some money with using this carb and free up some to put toward the heads. Too bad I missed out on those ported heads you were selling! One spot away lol. I’d love to go aluminum but the Buick heads are so expensive. The heads on the motor are stock 70 small valves.
  6. sailbrd

    sailbrd Well-Known Member

    750 is what a Q-Jet is rated at. So the CFM should be fine for your motor. The tune will be far more important. As Hugger said it will be great on the street.
    69SkylarkGS likes this.
  7. Mark Demko

    Mark Demko Well-Known Member

    A 2 bbl is more than big enough for a SBC:p

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