Pi head swap means pi heads, pi intake, and matching valve covers to the heads.
4.6l dohc B series heads swap means 4.6l dohc B heads, valve covers, sparkplug wires, 4.6l dohc B intake, dohc 4.6l front timing cover, dohc exaust manifolds.
4.6l dohc C series heads swap means 4.6l dohc C heads, valve covers, sparkplug wies, 4.6l dohc C intake, dohc 4.6l timing cover, dohc exhaust manifolds.
5.4l dohc either B or C series heads means, 5.4l short block, B or C heads, valve covers, sparkplugs, dohc 5.4l front timing cover, dohc exhaust manifolds, aaaand.....good luck with the intake. Their is currently no 5.4l dohc intake produced for either series, but has been in the past. A casted 5.4l C series intake named Sullivan are still floating around. Custom intakes are produced for either series head and expect to shed over $1000. Stock 5.4l dohc are gargantuan and would tower out of the hood, not to mention the intake looks stupid.
4.6l C series heads intake port is smaller than a 5.4l C series heads intake port, all other attributes are the same.
Stock cam selection is few and aftermarket cams are over $1100 for a set.
Supposedly the new 5.0l coyote intakes fit a 5.4l with C series head but require adapter plates. Alternator relocation will be required do to throttle body location.