There was a year when they were stick on from the factory I have one on my 64 after they filled the hole during restoration and forgot to re-drill it. I have an extra one i plan to put on the 03 Challenger.

2003 Dodge 3500 Diesel

1964 Plymouth Savoy White 2dr sdn. 512 stroked, Dominator, New Best 9.75 @ 138.50mph
2019 Challenger Scat Pack 1320 White Knuckle-K&N Cold air filter, Billit Oil catch can, drag radials stock 11.911 @ 114mph