There was a automotive manufacturer in the '60's that had factory supercharged engines for the general public, it was a domestic car company, Studebaker, they offered supercharged V/8's with dual carter 4 barrels, the ones that I remember were the golden hawk and the avanti, if memory serves me right the avanti had a 304 CID and the hawk was a 289 on no it wasn't a Ford 289. Studebaker was simply way ahead of their time.