Slant six bars are the same length as V8 bars for all A Bodies. Today we have a wide selection of various diameter torsion bars the will drop right in. Slant Six cars came fitted with 0.810” bars from the factory, and in my estimation, are way too soft making, for a great wallowing hog in the handling department.
Take a look over at Firm Feel to see a nice selection of bars. Other vendors carry different rate bars as well, so shop around.