I replaced my stock unit over the weekend with the BAT pump with the metal impeller. The old pump had a white plastic impeller and looked to be intact with no damage. My E1 SVT was built in Feb. '98, so not sure if that date is somehow indicative of when Ford switched from the black to the white impeller. The install went pretty smoothly - the most time-consuming part was scraping the old gasket from the housing. After 133K miles, the two had become rather intimate...!
