These custom made pulleys convert the old style vee belt arrangement to the late model 5pk multi vee belt that you find on all modern cars with only one tensioner. This is a far better system than the old vee belt. With the multi vee this dramaticly increases the surface area for a far better grip on the pulley, making them the only way to go high horsepower/ high reving 5litre & Stroker Holden power plants. They are produced from high grade aircraft spec aluminium making them exetremly durable & of the highest quality.
