Rossi's 6pk Challenger was probably one the top SS/FA cars in the country at the time, I'm not sure what the index was back then but you can darn sure bet knowing the quality and "engineering" of his cars they set and held many records.
Flash foward to 2010 and the current record holder in SS/FA(9.26@141mph)and EA(9.04@145mph) is Eric Bells 70 6pk Challenger..The difference in technology is amazing,yet the goal was still the same!
Kind of like comparing the original 68 Hemi Darts and Barracudas to the current SS/AH cars.