Hello, although this is an old article,
thought this might be of interest if you
haven't heard of it before:
http://www.off-road.com/4x4web/features/1999/02/

- that truck features ford's $180,000 R&D
produced 700 hp 5.4 32V V8. Naturally
aspirated (no N20 or alcohol), 2 big throttle
bodies, big 8 into 1 header, big 6" exhaust
(looks like it still has the cat from the
pic)

 

I wonder if that was a test bed for the COBRA R motor because it is a DOHC. Though the R falls way short of 700hp (385hp I think.)

Anyway, my dad has a Navigator 5.4 DOHC that we are currently building for use in his 97 GT Stang. Should see at least 450hp NA, if thats not enough he'll just have to call ATI.

Later,
Gabe