hi can anyone help me would like to know how big wheels and tyres i can go on my stock 70 challenger and what offset i might need i was thinking of 17 x 8 on the front and 18 x 9 or 18 x 8 on the rear running 275 wide tyre is this possible with the right offset any help would be greatly appreciated thanks  

I have a 73 Challenger and have Cragar SS 15X8 on the back with 4.25 backspacing.Im running 255x60xR15 BFG T/A tires. I can get my finger between the wheel and the lip of the quarter panel. The tire is only about a half inch off of the leaf spring. I measured and re measured the clearance. You may be able to get a 275x60 tire on without rubbing, but I was scared to try because I mail ordered  my wheels from summit.I have seen 295X60's on challengers before but the lip on the quarter panel had been cut and rolled.