Hp is difficult to achieve with stock 2v heads. The intake ports and tiny intake valve stalls to fill the chamber where piston speed is demanding.
The 2v 5.4l are not easily hp'd. Lucky to get 10rwhp over stock n/a
Ive whitenessed one station in northern indiana to carry 100octane...thats the only one Ive know of. I tell stories about it to my buddies.