Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

  1. K5Buckeye

    K5Buckeye Registered Member

    Joined:
    Mar 5, 2001
    Posts:
    75
    Likes Received:
    0
    Location:
    WA
    The Q-jet in my 72 needs replaced. The Jegs catalog suggests a 750 cfm. Is that what size came stock? 750 seems huge for a stock 350. What do you guys suggest?

    1972 K5
    1991 Jimmy
     
  2. Burt4x4

    Burt4x4 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    6,854
    Likes Received:
    0
    Location:
    California (Modesto area)
    Naa not for a Qjet. you have small primaries and FAT secondarys.
    I am running an Edelbrock 1901 Q-Jet. Have had it on my 350 for 5+ yrs now and it's been great!! I got it at Summit fer 350...

    72K5[​IMG]Led Zeppelin[​IMG]Rock ON![​IMG]
    <a target="_blank" href=http://www.geocities.com/baja/5099>www.geocities.com/baja/5099</a>
     
  3. Blazer1970

    Blazer1970 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,600
    Likes Received:
    0
    Location:
    Old Mission, MI
    Basically all Q-Jets are 750 CFM. GM used them on about 10 million 350s, so I would say they work OK. The way the secondaries operate on a Q-Jet, they only supply air/fuel per engine demand. This is different from a Holley etc.

    Tim

    70 Blazer CST 4X4 350 SM465 NP205
    87 Burb 4X4 350
    01 GMC 2500HD 4X4 Duramax/Allison
     
  4. arq

    arq 1/2 ton status

    Joined:
    Jan 17, 2001
    Posts:
    2,017
    Likes Received:
    0
    Location:
    Imperial Valley/Maricopa
    I just got the EDL-1901 Q-Jet, i love it. do a search on carbs and you'll find more info. what convinced me was the heat problem with the 1400series. 1900series is the way to go.

    ARQ.

    1-72 4x4 CST Blazer
    2-71 4x4 CST Blazer
     
  5. K5Buckeye

    K5Buckeye Registered Member

    Joined:
    Mar 5, 2001
    Posts:
    75
    Likes Received:
    0
    Location:
    WA
    Thanks dudes! I was just comparing the q-jet to the 750 DP on my Chevelle 396. Guess it wasn't apples to apples. As you can see, I'm not too versed when it comes to motors and stuff. I kind of plug and chug, ask questions later. But not this time!!

    1972 K5
    1991 Jimmy
     
  6. Roostr84

    Roostr84 1/2 ton status

    Joined:
    Aug 19, 2000
    Posts:
    451
    Likes Received:
    0
    Location:
    NJ
    Just an FYI buit Q-jets come in both 750 and 795 cfm.

    Chris =)

    I think the exhaust fumes have finally gotten to me!!
     
  7. Steve_Chin

    Steve_Chin 1/2 ton status

    Joined:
    Mar 6, 2001
    Posts:
    1,126
    Likes Received:
    0
    Location:
    Foster City, CA, USA
    The easy way to tell the 750 CFM Quadrajets from the 800s is to look in the primary sections. The 800s either have the second booster rings milled out of them or have larger main venturi in them. The larger main venturi are characterized by a couple of "bumps" below them (visible if you look up through the throttle body), where the 750s are smooth. One can take an 800 CFM carburetor and mill the second set of booster rings out to achieve about 860 CFM and more massaging can get a Quadrajet well over 900 CFM. The strange thing I have found is that most of the Chevies seem to have 750s on them and later Pontiacs (after '75) have 800s on them.
     
  8. Roostr84

    Roostr84 1/2 ton status

    Joined:
    Aug 19, 2000
    Posts:
    451
    Likes Received:
    0
    Location:
    NJ
    Also it is good to remember that while the carb is rated at 750 or 795 cfm many do not flow that much. I know my Monte carlo had a supposed 750 cfm q-jet stock but in reality it flows somewhere around 560 I believe

    Chris =)

    I think the exhaust fumes have finally gotten to me!!
     

Share This Page