In street applications they did. Holleys were available as part of the dealer performance packages and all of the racing setups used them spec'd from the factory. Max Wedges and Race Hemis were set up with Holleys. I have an MP engine "bible" and it specifies one of the first steps when modifying any setup for performance is putting on a Holley carb. That book is basically a compilation of official Chrysler performance bulletins from Chrysler engineers.