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Ok I searched, but wanted your opinions.

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Old 04-29-2012, 10:01 PM   #1
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Default Ok I searched, but wanted your opinions.

I have a 1972 Chevelle with a LQ9, patriot 226 cam, turbo 400. I'm planning to run a single plane of some sort, long tubes and a 3400-3500 stall, Gears are 4.10s. I have a 750 Holley vac secondary carb from the last engine, should I reuse this carb or should I step up to a bigger carb or another 750 with mechanical secondaries??? I plan on swapping the heads out later to a set of SDPC cnc'd 243s.
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1971 Malibu. LQ9, prc stage 2.5 243's, Custom grind, Vic Jr., Long tubes, 850cfm holley DP, 125hp plate kit, TH400, 4,000 stall, BOP 10.5 ten bolt, 4.10s
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Old 04-29-2012, 11:08 PM   #2
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I know it takes time to get responses. 71 views later, I figured I'd have a couple...
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1971 Malibu. LQ9, prc stage 2.5 243's, Custom grind, Vic Jr., Long tubes, 850cfm holley DP, 125hp plate kit, TH400, 4,000 stall, BOP 10.5 ten bolt, 4.10s
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Old 04-30-2012, 05:22 AM   #3
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If your just making a cruiser that will work but if your wanting to make some power go with a mechanical.750 or 850.. I ran a 75010 vac sec. On mine and could only get 119mph out of it went to 850 and picked up to 124 with my old lq4.
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Old 04-30-2012, 05:24 AM   #4
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That was supposed to say 750 vac.secondary
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Old 04-30-2012, 06:43 AM   #5
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I take it you are setting this up for the track? You will be moving a good bit of air with that cam and ported heads. I'm sure it could use the extra CFM up top so I would think at least an 850 would be a better choice. I would be tempted to run what I had for now and upgrade later.

Mechanical vs. vac secondary, I don't know what to tell you. Some guys on here say never run a vac secondary cause they cost HP up top. Holley only recommends them for light weight, low gear cars with manual transmissions.
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Old 04-30-2012, 08:04 AM   #6
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The 750 will work, but a mechanical will get the max air to the engine, and larger cfm is a plus as stated.
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Old 04-30-2012, 09:40 AM   #7
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Thank you guys.
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Old 04-30-2012, 10:12 AM   #8
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I would not run a vacuum secondary carburetor with a high stall converter over 2500.
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Old 04-30-2012, 11:59 AM   #9
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If you need, I have killer deals on Proform/Quickfuel Carbs in stock
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Old 04-30-2012, 11:59 AM
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