Well there not pricey at all I don't think, especially for the level of performance it takes you to from where the bolt-in lump fall short. Your only going to go so fast with a $70 dollar piece of aluminum bolted inside the head. Im sure Sissell considered that at the beginning, the first prototype that was sent to him for him to test was a piece of sheetmetal that was held in place between the head and intake manifold gasket surface. He just refined it into the brazed lump he later became noted for.
