When GM High-Tech Performance magazine needed a custom double-pumper they called on the best - Racetronix:
"GMHTP has used Racetronix fuel systems in several projects recently, with outstanding results. So when it came time to give the Buick more fuel, I contacted Jack. Although he didn't stock a double-pumper setup, he was willing to create one for this project using a stock sending unit, that would run one fuel pump under normal conditions, and kick in both pumps when the boost comes up."
See the PDF version of the story here.