We're quoting the new and old axle ratios because a numerically higher rear-axle ratio necessarily reduces measured rear wheel horsepower on a dynamometer (again, for reasons that would best be described in a no-holds-barred engineering analysis). But you can see that the gear ratios used in both of our new rears were virtually identical, so this factor can pretty much be taken as a constant in comparing the percent loss difference between the two axle assemblies (though before and after dynoing on different days probably should not, even with our use of SAE correction factors).
A final note on the M9 is in order because of its fully adjustable torque arm system. Readers should be aware of what a well-constructed piece this is, and think about the fact that it was included in the price of our M9 assembly. Once installed, we adjusted this system to provide the Moser-recommended 1 degree of downward pinion angle (compared to the driveshaft angle) before hitting the dyno, and while no track testing of any sort has been done thus far, the system has performed admirably on the street, with the exception that some extra engine and road noise is now transmitted into the passenger compartment (thanks to the solid rod end connection between the torque arm and the transmission crossmember). We're confident this unit will help us put down some sick 60-foot times when the time comes to hit the strip. The system feels like it would perform admirably on a road course as well (the latter assessment is, of course, a bit subjective).
As to his new S60, Jensen is enjoying it very much. While it needed a quick Panhard adjustment to center the rear, and does transmit some gear noise into the cockpit, he's impressed with the ease of installation and can't wait for Raceway Park to open back up to finally do some high-rpm clutch dumps!
In conclusion: Both the Strange S60 and Moser M9 have duly impressed us so far as top-notch, high-strength rear-axle assemblies. While each has features and aspects better tailored to different customers and vehicle applications, both are high-quality choices. We look forward to hitting the races with these cars once the snow melts, and will keep you posted with our results!