^^^^^^^^^^^^^^^^^^Impossible and will never happen. Last time I checked, most builders don't manufacture the actual parts and you are always at the mercy of the companies that do.
Prime example......seems KB promises blocks in 6-8 months, have we seen anybody get one in less than a year. I have a 3 month crank, ordered from a VERY reputable crank maker now for about 5 months. Have a set of "be ready in 6 months" heads that I am still waiting on two years later. A builder would be a fool to put a time guarantee on a motor, because HIS suppliers said they would have him parts in X amount of time. And don't say swap suppliers. Customer wants a KB block for example, where else would it be suggested to buy one