For example, right now your out of your head, if you needed a 600 hp street 482 you could get those numbers with a ported E head, what would be the disadvantges by not using your head, is it just the extra machining involved to get the E head to perform like your as stock or slightly worked on, for example keith craft racing will only use the E head with there machining, do they not like or use your head even if it does out perform, it sees a no brainer everyone would want to use the best or what would appear to be just as good with less head work involved...most builders I have spoke with will use all heads if need be, (brands)...