You should measure the room you have in your fender wells with the current tires & rims you have now from the inside
of the outer finder lip to the frame/ inner finder well for width and the max room from front to back within the fender well as well .
Other items can also obstruct your rim & mounted tire, eg. lower shock bolt / exhaust pipes/lower part of the outside of the front part of the fender well, etc .
Backspace of the mounting rim plays the biggest part in whether a rim & big tire will fit in your cars rear fender wells .
Here is some more info -
Here is a site to look at https://www.rsracing.com/tech-wheel.html#fitting
Basicly there are various measurements to be made within the rear fender wheel wells;
(these measurements are for my car's rear area based on a
Cragar SS 8”Rims BS 4.25” / BFGs 275-60-15 RearTires SWW 11”)
1. RIM SPACE inside curved lip of Rim to bottom part of Shock Nut for DR & Pas Sides
(DR Side = 1+” PASS Side = 1+”)
2. OUT SPACE from inside Lip of outside Fender to Side Wall of Tire for DR & Pas Sides
(DR Side = 1” PASS Side = ¾”)
3. IN SPACE from Side Wall of Tire to Frame/inside face of Fender for DR & Pas Sides
(DR Side= 1 ¼ ” PASS Side= 1 ¼ ”)
4. WheelWellSpace from inside of bodyfender to frame/fender = 13"
and from grd to top of the inside of finder = 31” + hi / diam
5. SPACE from Face of Rear Brake Hub to Shock Nut = 5 “ DR & PASS sides
6. SPACE from inside of Fender to Face of Rear Brake Hub = “
7. Rear End Width –Face of Backing Plate to Backing Plate = 53.25“ and
Face of Brake Drum to Brake Drum = 60 “
8. SPACE from Front of Fender Well to front of current tire when mounted to rear end .
You should do a lot of research and measuring into this before ordering any rims and tires you want that will fit within the wheel well space you have / will have available .
Also consider that you need more clearance when cornering than when the car is going straight because the tire can "lean over" in cornering situations.
On the straight away it is OK but on corners it could scrape the hell out of a sidewall.
Shoot for AT LEAST 5/8 clearance between the sidewall and the fender lip. Have some friends sit in the back seat
when you make these measurements to compress the springs. A full tank of gas will help also.
You need to measure clearance at the closest point between the sidewall and the lip.
If you don't measure at the smallest clearance point with a few guys in the car and a good bump when the gas tank is full and presto...
no more sidewall on your tires.
If you need more info or have any questions just ask . Good Luck