I've been trying to avoid this $...storm but I have to reply to this partially correct information:
"As to dynos, the fact is indisputable, dynos do NOT measure horsepower. They are incapable of doing so. They measure torque then use a mathematical formula to ESTIMATE horsepower."

Some dyno's are just as stated above. They measure torque by applying a retarding force to the rollers, and the engine opposes it. Due to tire/roller slippage and difficulty of measuring the retarding force accurately, these dynos may or may not be very accurate.

Others like the Dynojet 248 measure hp directly and calculate torque. HP is the rate of doing work and the Dynojet measures the time to accelerate a roller having known slugs of intertia. As a bit of trivia, they measure the slugs by spinning up the roller with an Olds engine as a "mule" and then measure the time for it to decelerate from one rpm to a lower rpm. The rpm is easily calculated to miles and time in seconds is converted to hours, giving mph. Rate is measured time to accelerate from one mph to another, giving HP accurately, reproducibly, and directly. Torque is calculated if rpm of the engine is known; a probe is attached to the crank of a diesel or the ignition system of a gasser to measure rpm. More recent Dynojets have a very good knurling on the roller to minimize tire slippage even on very high HP engines, such as Cummins diesel pickups with 800 or more Hp at the wheels, and double that in torque.