SAE engineers (not owned by mopar) rated the 8.75 over the 9 inch----and the dana 60 over both as stock units......if you want to spend lots of money and be able to say 9 inch all the time then build a 9 inch---the aftermarket chased the 9 and made it what it is today---the same way the aftermarket chased the SBC and made it what it is today....maybe we should all be putting chevys in our muscle cars--it only makes sense...