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Mea Culpa
My math was WAY off on this. I don't know what I was thinking, entered the wrong values into a calculator, mislabeled components, or just brain freeze, or whatever, but here's the corrected version:
First, since the resistor goes to ground, a low value cuts the volume, so I went with a much higher value and there's hardly any volume drop. So, the corrected circuit uses a .0047uf capacitor and a 220k resistor for High Pass at ~153 htz or a 110K resistor (I used 2 220Ks in parallel) for High Pass at ~307 htz. I wired a switch so I can use either. The High Pass at 307 htz retains a real beefy low end which is the one I prefer. Flipping the switch to set the High Pass at 153 htz still has decent bottom end, but has a bite more like the the unaltered pedal.