Will my new alloy wheels fit my skyline without mods?

I have a 4 stud hub in my skyline currently runs stock steel 16" wheels with 205/60 tyres,I have bought a set of17" alloys with 203/40 tyres they are same stud pattern but offset is 40 and my hubs are offset 25 will in need spacers on all wheels,if so do I need 15s spacers to make up the difference,the formula to work this out is more complicated then my physics education will cope with Thanks