If you mean dropping a 15" logicboard into a 17" case, no.
All the ports and the internal layout will be wrong. Parts will be wrong. For instance, the 17" PB has a DC-In board with the modem port all by itself, but the 15" DC-Inboard includes the USB ports.
If you mean, extensive modification of the logicboard to make the ports line up and work, then well…good luck with that.