PI stands for...
#17
For our test, we focused on the 4.6L Two-Valve GT motor circa 1999. Ford took steps to improve upon the original modular motors by offering the Power-Improved (P.I.) versions starting in 1999. The new-for-1999 P.I. motor featured improved breathing courtesy of revised cylinder heads and intake manifold.
#22
#25
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#28
Picture this: 100 years from now two old farts rocking on a porch somewhere in the deep south. They are arguing about weather it is a power improved head or a performance improved head on the engine that was in the 1999 F-150 that was found in a barn last month by the first fart's grandson.
Regards
Jean Marc Chartier
Regards
Jean Marc Chartier
#29