Alignment with ductile-iron rockers?

I have springs on the set in my Challenger, been that way for over 100K trouble free miles... I swapped out the heads & cam about 20K miles ago & considered going to spacers but decide the springs had never given me any problem so why change them...

All the Mopars that originally had adjustable rockers used springs & those have a good reputation for trouble free operation as well...