1973 dart swinger rear tire

whats the biggest tire you guys have got under the darts, with out moving the spring and mini ?????? i tried my 15/8 draglites ,with 28/10.5 m/t slicks and they just will not fit....i'll have to change back space to make it work....i have a 27/10.5 hoosier qtp i can try just dont want to take the tires off and put the others on and they still dont fit.....i think the section is about 1" less on the qtp but not to sure....i was thinking of keeping the rally wheels and mount some drag radials but money is kinda short right now for that....i just didnt want to have to do the back end of this car....:violent1::violent1::violent1: