Mike, apart from the 16"/17" difference, they both run 7 spokes, and the centre of the rim(immediately around the studs) has a slightly deeper dish than the 16" wheel.
Minor difference that really looks the part.
@ Andrewbuch. After the engine overhaul, AND the radiator replacement, and with Christmas fast approaching, I might just leave the 17" wheels for this year. Maybe soon next year.