FBO's black HEI ignition box

RustyRatRod said

I know people talk about the high RPM retard on some of these ignitions as if it's a bad thing. It's not always. If you have a combination that's on the ragged edge (as is all the rage these days) you may find high RPM retard desirable. You don't WANT the timing as far advanced as possible at high RPM in some of those combinations. It might be a recipe for disaster.

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That’s exactly why you have to test for it. You might be surprised that most NA cars want MORE timing in low gear, “standard” timing through the middle and MORE timing again in high gear.

It depends largely on load and VE in high gear

If you don’t know when an ignition starts to retard and when it retards then you have no idea what you actually have for timing.

I used to advocate for (and did it all the time) locked out advance on most any performance build.

Once I learned about ignition retard is STOPPED doing that and build some kind of curve for everything.