Scott;
My spare set measured 45" total length. I got them from ALL CLASSIC MOTORS in Velva, ND. About $30ea.
I have read discussions about whether standard '67/68 torsion rods are different from HCS/CS rods. I don't believe they are. If anything, the fiberglass decklids are lighter weight than the metal decklids. And if so, not by any appreciable amount.
Neil