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  1. #1
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    Default 308 carby choice

    Hey guys, long story short looking for anyone running an 1850 holley 600 vac on a decent 308, engine has 10.1 comp vn heads dual plane 286 crow equivalent cam rollers stage 2 auto/ 2800 stall 3.45 rear, is the 600 enough- feels good on the street, had a 750 dp previously from old owner amd massive improvement with the 600 just have read some say they at limits with mild 308 as my setup should be around that 180rwkw mark

  2. #2
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    hi

    How Big A Carb Do You Need? - Hot Rod Network

    308 x 6500rpm x ve volumetric efficiency 100 %
    divide by
    3456
    =579 cfm

    http://documents.holley.com/techlibr...carburetor.pdf

    Depends really on how much street or strip use the car will see
    Last edited by swampy; 28-02-2018 at 01:58 PM. Reason: none

  3. #3
    been here .......too long Smitty2's Avatar
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    I run a 800cfm Quaddie on the race car...
    __________________________________
    ONE OF THE Aussie V8 MODERATOR/ADMIN TEAM
    Never late in an AussieV8!
    Club circuit racing...the best fun you can have with your pants on

  4. #4
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    The 350hp 350 in 1969 Corvette ran a Quadrajet, exact same carb I’m fitting to the 350 in my HK. Similar specs to your 308 other than the extra cubes: 11:1 LT1 alloy heads, dual plane, similar hydraulic cam but with 112deg lobe centres, roller rockers, 2800 stall, mid 3’s rear axle. HK and HT and later VK and VL Group A won Bathurst with these carbs.

  5. #5
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    I have a OEM Quaddie Insulator/Spacer and 308 Blue motor Primary and Secondary needles if you choose to go that way.

  6. #6
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    Did you keep the 750? Problem with the 1850 600's is that they're fuel metering is pretty crap. The 750 DP will at least give you the option of changing secondary jets, have 4 corner idle adjust, and depending on which model it is, adjustable air bleeds. Read up and I'm sure you'll reach a better outcome with the 750.

  7. #7
    Do you ever leave? EH179's Avatar
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    Yep, the 600 is very limited in tune ability, with a sec' metering plate rather than a block.

    Trade the both of them for a 650 hp dp...thank me later

  8. #8
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    ^^^^^ Yep

  9. #9
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    Hi

    A quadrajet has very small primaries and large secondaries . The key to getting the best of both worlds . Rated about 780cfm

  10. #10
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    650 Is plenty . If you already have a 750 use it and just tune to suit . 350lj

  11. #11
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    Not really fussed with quaddys sorry guys- don't get me wrong they can be great, its more finding good ones to begin with and then people who know what they are doing with them, didnt keep the 750 it was athsmatic on car- not overfueled just far too big in terms of air speed it was rubbish down low with my setup, the 600 feels great upto 5k car will be streeter so not overly fussed by above 5500rpm just seeing if anyone had decent results over say a 750 vac, dp more suited to manual or larger converter diff gear setup

  12. #12
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    As above, 650dp all the way. Ran one for for 20 years on a mild/hot 308, perfect. When the car returns to her former spec, it will go straight back on without hesitation.

  13. #13
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    [QUOTE=Slx308yah;744609]Not really fussed with quaddys sorry guys

    DP Is suited for anything really if setup right. As mentioned earlier the problem with Vac Sec Holleys is that they run secondary metering plates instead of jets which is a pain in the ass. Remember DP carbs only start to open secondaries after 40% throttle opening. So cruising etc will mostly be from your primary side. And personally I hate chasing secondary springs for tuning. If you want a good budget Vac Sec Carb. Get a QFT Slayer. they have Secondary Jets, Choke, Adjustable Air Bleeds and the Vac opening adjustment is done via a screw instead of swapping out springs. Great Carb for the money.

  14. #14
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  15. #15
    Do you ever leave? HQ308Ute's Avatar
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    i use Quickfuel carbs, nice bit of work imo.

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