oh brother.. where you reading that? a 1971 magazine? its pure bullshit. the 727 it a big power hogging boat anchor.. a 904 will hold up to gobs of power if put together proiperly. no need for exotic parts either..
the slant six 904 won't bolt to a 318 though so you would have to find a v8 904..
i beat the hell out of my 904 from 2005 till 2015 both at the track and many street miles.. when i had it freshened up just because it was going into another car.. other then a couple hard seals i could have just bolted it in if i wanted...