I agree there. The chevy boys have been modifying for shafts and girdles and the like to make their junk strong enough to live with big springs and at healthy rpm. Mopar can probably get the job done with stock shafts and factory iron rockers.
Yes, wellll, Magnums do not come with shaft rockers so you are back to following the Chevy and Ford guys lead, stud girdles or engineering a shaft system.