What the hell does drivetrain loss have to do when calculating RPM speed for gearsets? This is why I don't watch the "power block" or take anything associated with them seriously. Drivetrain loss has 0 to do with your RPM turning at X speed and the gears in the trans/rear making your tires turn at Y speed. The only way it MIGHT come into account is on an unlocked torque converter.
site has been around forever, like literally at least a decade and will tell you exactly what your RPM speed should be with your final drive ratio, rear gearset and tire size.