Tire size for 67 gtx

Just wanting to see anybody know what the widest rear tire you can put on stock susp. 67 gtx.Thanks

I Have 245 BY 15'S ON MINE AND I CAN INSTALL REASONABLY WELL WITH JUST A FLOOR JACK. THESE ARE STOCK WHEELS. I know of some who have done offset work on stock wheels and gotten 275 by 15's on. Biggest I know of without moving springs or doing tub. I know a 29 inch tall tire will fit but also will rub the qtr on bumps..don't recommend unless suspension is super tight. I have 26 inch tires with 355 gears and that is a very nice combo as far as I'm concerned. All the tires are 60 series except the 29's...they were 70 series. Love the car...hate the wheel wells