tire clearance issues

ok guys, I need some direction on rear tire to fender clearance on my 72 dart other than different rims with a deeper offset (not in the budget). I have 235/60/15 tires mounted on cragar ss 15x8 with 3.5 in offset, I just put air shocks on as regular shocks didn't work and even with 110-120 lbs of air pressure the fender is still on the tire. What are my options shock extensions or are there any other options if shock extensions are they still available? Thanks