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Old 11-10-2017, 09:40 AM
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572Camaro 572Camaro is offline
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Good morning. I noticed no replies yet and you are planning to do the work this weekend so let me try..,
Dual plane intakes can create fuel charge reversion which carbs like but self learning EFI systems do not. I have tuned EFI systems where dual plane intakes have caused issues like surging and hard to control air/fuel ratios.
If it were me, I would take the time and money, and convert to single plane intake.

Next, what are your tubing diameters? I would prefer 3/8" minimum supply and return. I personally run 1/2" supply and 3/8" return on my 572ci beast. With you running a 350ci, 3/8" diameter supply would be fine. As far as return line, do the test. With ignition on, fuel pump running, engine off, set your fuel pressure. If it controls, you are fine; if it climbs, you need a larger return line.

Now for a few other things..,
What is your idle vacuum reading in "Hg? I like to see at least 10" of vacuum at idle with engine warm. The reason is when self learning systems learn, they need wider variations in manifold absolute pressure which is the primary indication of load.
What are your cam specs? Lobe separation angles between 112 and 116 is optimum for efi.
Finally, be super careful when you run wiring.., keep your efi wiring away from noise producers like spark plug wires, ignition boxes, etc
Please reply back and let me know .., I want to help!
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