...I owned an original '67 L-78 Chevelle from '78-'84 and throughout those years I also had seen various ads for "original 427 '67 Chevelles". From what I recall, I thought I had read in various publications(Hemming's, Super Chevy?)that up to 50 1967 427 SS Chevelles were built. This was also 25+ yrs ago. There was that one book I had yrs ago by Terry Boyce "Chevrolet Super Sports;1961-1976". Not sure if anything is mentioned in that, but I remember that book was before 612 L-78 '67s were known to have been produced and the book said "Possibly 100 '67 L-78 Chevelles were built for public sale".
