road rated slicks

Hi all i am planning on taking my 1969 dart swinger to the track this summer .It is a restored 340 4 speed car. Still running the 4 inch bolt pattern. has anybody used these tires and what size of a rim should i be looking for . I found a set of 15 inch x 7 small bolt rims on Ebay for a good deal how big of a tire can i use for this rim? Or should i try and find an 8 inch rim . Also what size of an offset should i be looking for to fit properly under the car. Does anybody out there have a set of tires and rims small bolt pattern that they want to part with for a reasonable price.
regards