what size tire can i fit

[2 fast z28]

hi guys looking to do a spring relocation kit on my 71 dart swinger i have super stock springs in the car now just wondering what size tire can i fit in the back wheel tubs with just moving the spring or is it better to move the wheel tubs in also and if i have to move the wheel tubs do i also have to make the back seat smaller the car is going to be just a cruiser and weekend fun on the street and sometimes maybe on the track its going to have a mild build 340 and either 3.55 or 4.10 gears let me know what u guys think thanks much

 

[74DartSwinger360]

My friend has a 69 dart with 3 in inboard spring kit and 15 inch magnum 500s with custom backspace and is running 295-75-15s on the back no rubbing.

 

[Vincent855]

There are many company for tires i want to some number of company those are good for tires.Alliance Tire ,Apollo Tyres,Bridge stone,Yokohama these company are famous for tires and rim.