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Old 07-01-2012, 07:39 AM
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Based on your latest post, is very likely that you can fix the problem with only step-up springs and primary rods. These are very easy to swap.

All the primary rods have two steps, for cruise and power, and they are marked with numbers like 7547. The larger number is the cruise step and the smaller is power. A smaller number means a richer mixture, since the rod sticks down into the jet and reduces its flow. You could try something like a 7542 or 7537, which would keep cruise the same and richen the power mode.

Vacuum pulls the rods down into the jets so that the thick (75) part of the rod is in the jet (cruise). When you accelerate hard the vacuum drops and the springs push the rod up so that the thin (47) part of the rod is in the jet. The rating of the spring determines how low the vacuum has to go before it transitions from cruise to power. A higher rated spring (e.g., 8") will transition to power sooner than the stock 5" spring in the 1406 when you accelerate.

You may also need to adjust the accelerator pump shot, but I would try that last. Many folks try to fix the Edelbrock bog with the accelerator pump, while the real fix is (1st) get the right step-up spring, and (2nd) pick the right primary rod combination.

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