No secrets (yet).

Here are the numbers from my spread sheet.

Tire Diameter Calculator
tire diameter = 2 x selection width x aspect ratio / 2540 + rim diameter
Width Aspect Ratio Rim Diameter Tire Diameter
225 60 15 25.62992126

MPH Calculator
mph = rpm x tire diameter / differential gear ratio x 336/ transmission gear ratio
Differential
Gear Ratio 1st Gear 2nd Gear 3rd Gear 4th Gear 5th Gear
3.909 3.74 2.136 1.36 1 0.856

Puts me at 6900 RPM in 5th on paper

AEM Log shows 6984 RPM, actual.