How do I make him understand?

[Mach 1]

The AOD's shortcomings as a performance transmission are well stated above, but Ill go one step farther, and declare that on a mildly modified 5.0 (most street cars) that an AOD with a shift kit, lower gear ratio and a high stall converter will STILL lose to a 5 speed car.

Those items help, but arent enough to make it equal to the 5 speed. Theres just to much lost in the way of efficiency and weight.

Stall converters, shift kits, and gears arent enough to make up for the horsepower lost through the less efficient automatic transmission. The AOD is said to eat up around 40 horsepower more than a 5 speed due its design and efficiency, which is true.

Gears, converter and shift kit arent going to replace that 40 horsepower.