From pivot point on the lower control arm, to the attaching point at the transmission crossmember. Front to back. Do not mix them up either. Left bar stays on left, right bar stays on right. Otherwise they will fail in short order. They are spring steel bars with a left or right twist. Do not nick or gouge the torsion bars either when getting them out or putting them back in. A gouge or nick in the bar will cause it to fail later on. Yes they run alongside the framerails, about 6" or so inboard of them all A bodies from 1960 up thru 1976 the torsion bars are like that along with B,C, and E bodies. Others on here can give you the easy way of pulling it all apart. With what you got rustwise I'd say. Prob some WD40, impact gun, bernsomatic torch and a BFH to take it all apart.