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Old 12-12-2012, 10:14 PM
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750 downleg or 650 straight leg on a SBC 350

which carb would run better. 750 DP downleg booster or 650DP with straight leg booster. 350 sbc roller cam, 227@50, .565 lift on 108LSA, vortec heads with 180 intake runner, eddy air gap RPM. 1 3/4 LT headers, 390 rear gears, 700r4 with 3.06 1st gear and 2,500 stall. It is a weekend car not a daily driver. Thanks 4 the help.

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Old 12-12-2012, 11:03 PM
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The 750 down leg carb body is always better. especially the HP style carb
The Holley /Proform 750 HP carb body is a great cool upgrade for any straight leg 650-700-750 DP
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Old 12-12-2012, 11:21 PM
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still the 750 same as last time
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Old 12-13-2012, 02:09 PM
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Originally Posted by cadillacdave1 View Post
which carb would run better. 750 DP downleg booster or 650DP with straight leg booster. 350 sbc roller cam, 227@50, .565 lift on 108LSA, vortec heads with 180 intake runner, eddy air gap RPM. 1 3/4 LT headers, 390 rear gears, 700r4 with 3.06 1st gear and 2,500 stall. It is a weekend car not a daily driver. Thanks 4 the help.
Downleg, that make three votes.

Bogie
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Old 12-13-2012, 05:02 PM
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My only concern was that a 750 may be too much carb for a 350. Also the carb on the car now is a holley street HP 650 Dp, with straight leg boosters. Final question since everyone recommended the down leg. Would the down leg boosters run better or an annular 750? Thanks for the help.
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Old 12-13-2012, 05:11 PM
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Quote:
Originally Posted by cadillacdave1 View Post
which carb would run better. 750 DP downleg booster or 650DP with straight leg booster. 350 sbc roller cam, 227@50, .565 lift on 108LSA, vortec heads with 180 intake runner, eddy air gap RPM. 1 3/4 LT headers, 390 rear gears, 700r4 with 3.06 1st gear and 2,500 stall. It is a weekend car not a daily driver. Thanks 4 the help.

You have a pretty aggressively configured engine, therefore, a 750 will be just about right, especailly since you say it isn't a daily driver. How it gets used (driven) really affects the booster style, a dog leg builds better mid RPM torque without limiting the top end power than does a stright leg booster. This will be really good for a weekend warrier. For a high power street engine the annular would give better manners stoplight to stoplight but will take a little top end power off.

Bogie
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Old 12-13-2012, 06:31 PM
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The car is totally streetable as it is with the 650dp, good street manners, no hesitation or lugging at any speed. I guess the 750 DP with the downleg is the way to go. Does the downleg booster also give a better signal at idle? Would you recommend the 750 DP or vacuum secondary - with the downleg booster? Thanks again.
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Old 12-13-2012, 06:59 PM
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750, double pumper,they work
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