Actual crank/prop centerlines are the same if I remember (which is questionable), but the 6 has a setback compared to a 5 (unless the 5 is on a box), so the ideal X is higher.
If it is a driveline setup it's not too bad as the u joints will take the offset, fill the transom & go for it. A plug-in really requires a re-rig to do it right.
I can look at the drawings Monday (or email them to you) if you want.