a body spring quandry..HELP.

i have a 72 duster that i am running 275/60-15's on .i have torque thrusts 8 1/2 wide...I need to raise the rear to keep the tires from rubbing...my current 30 plus yr old springs with outdated air shocks are not gonna cut it...My questions are...do I buy a new set of hd"s from mancini? Do I buy a set of superstocks???.I need 1-2 inches over what i have now( stock 340)..any and all input welcomed...

Might consider the JR springs from JC whitney. May (still)have free shipping & the price was good. Never used it as they sent the wrong one (yes just one, an F body one w elongated end ) but it looked stout & after I sent it back I ran into another good deal so I never got the right ones but others have & have liked them & I understand they fixed their shipping/numbering system.

This is how my 68 Barracuda sits with the Mancini XHD springs.