another good read is the Allpar "history of mopar squads" from the 1930's till modern times---also my mistake it was the 1969 polara that held the records until beat by the 2006 hemi charger-----it also said in 1969 85% of squads in north america were plymouth-----the california market was so important to chrysler that chp had a custom cam grind available only to them....the mopars graded out better because they had heavy duty suspensions--bigger brakes and skid plates.......