Educate me- What was the diff between the 1969 Plymouth Roadrunner and GTX?

[pink panther]

sport satelites are often cloned to the RR, I have always liked the GTX package though.

That was the idea.

Except this car would have been the Dart, a wanna bee muscle car back then, only dorks had them as a wanna be muscle car, but spanked many a RR & GTX and E-body.