Originally Posted By 72Swinger
When you look at what they cost already setup with bronze guides and .650 lift springs ready to go, and the cost of having a set of stockers put into that same condition, they are cheaper.

This plus they are cast from 356 t6 aluminum unlike the lower quality alloy used in the stock heads. I called Edelbrock on this and they said they are a ways out yet so my guess is at least 6 months.