At 400+hp, What kills A904s?

"and takes notably less power to turn than the 727"...wtf does "notably" even mean? I've seen "60 horsepower" listed as the amount between a C4 and C6...Idiots take out a low gear 999 and stick in a New Yorker 727 (along with its low stall converter) in a Duster (with no kickdown) and then claim that all 727s are pigs. I've seen the same anecdotal argument against the th400 compared to the th350. (Some say I'm 'relentlessly persistent', but I take issue with such statements...)