You may need a new bottom bracket if you change the crank but, assuming your current crank is a standard (JIS) square taper, the old one might be ok. Your front derailleur may have to be replaced if the cage curvature is too much for the larger chainrings.
Your frame will probably have to be respaced for anything more than the current 5-speed cogs if it has 120 mm dropouts and for anything more than 7-speed if they are 126 mm.