young and need help

As a general guideline rim width on disk brake equipped/stock suspension A body you will be limited to a 15 x 7 with a max back space of 4.25". The contact point is the upper ball joint and the wheel's rim. On a 17" wheel the contact point is the tie rod end and rim. Back space around 5.5 - 5.75", though variances will occur with anything non stock.