Does anybody know about wheel spacing?

[rbull51]

We have got a standard rover 600 and are trying to fit rover 800 turbo 17inch alloys to it. But...there is a lot of wheel wobble. Does anybody know what size spacing i need to stop this problem??? Original wheel size was 15inch, 195 width tyres with an offset of 6j. New wheel size is 17inch, 225 width tyre and an offset of 7j. How do i measure what spacing i require... Any help will be much apreciated.





(please dont move this thread to wheel and brake section)