yo Bob,
According to a pal in another area; "due to PCV breakdown and carbon build up in the #8 cylinder. Ford believes that by moving it (he is referring to the PCV valve vacuum supply hose) to it's new location, it will not be as likely to load up and fail."
In any event, Ford did change the routing in 94.
Here is the original Non-Ford info source for this, where only #8 is cited;:
Source: by fourstarengines.com
"Failure of the #8 piston or the #8 rod or rod bearing in Ford 5.0L, V-8 gas engines
Applications affected have been in 1987-1993 pick-up trucks and vans. After discussing the situation with several installers, the problem has been narrowed down to the PCV system.
Solution:
During engine installation, reroute the PCV valve vacuum supply hose. Follow these steps:
Plug the 3/8" (pipe) thread hole in the rear of the plenum where the PCV valve hose is connected.
Drill and tap a 3/8" pipe thread hole in the center of the plenum and thread the PCV connector into it.
Reconnect the PCV valve vacuum supply hose to the new location.
Be sure the drain hole in the baffle is open. The baffle is under the PCV location in the valve cover.
Installers who have rerouted the PCV system and opened the baffle drain hole have not reported any #8 cylinder failures.
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