Ford's Boss 429 Mustang - Exclusive Photos

Ford insisted on the modified Fiberglass body for the Mr. Gasket Gasser.

The motor made 1800 horsepower on the dyno with the twin turbos!

Kaase Cylinder Head
Rocker stands aren’t used on the new Kaase heads as they were originally, rather the new Boss Nine head has a cast in boss that does away with stands all together. The exhaust rocker is slightly longer, taking some angle out of the pushrod, while also moving the pushrod away from the block deck...

...avoiding a previously mentioned pitfall of using original Boss 429 heads on a standard block. Another benefit of the revised pushrod angle is reduced side load on the lifter bore, a real advantage if running a solid roller cam with lots of spring pressure.

Kaase Intake Manifold
The new Boss Nine intake manifold is a single-plane unit that stands just 1 1/4 inches taller than stock, and can be used on either Kaase or original heads. Available with either a 4150 or Dominator flange, dyno testing has found this intake to be worth big power over either a period NASCAR spider intake, or the stock dual plane. Unbelievably, on a stout 466-inch mule, the Kaase intake was worth about 50 hp more than the NASCAR piece and 100 horses more than the stocker.