That's an interesting chassis you have there.
Torsion bar selection for the 73-79 may be more challenging than the equivilent E body as they are a different length, but, I think Firm Feel is doing bars for them now, so you might be in luck. If firm Feel can do custom bars, you might consider ditching the B body t-bar sockets and replacing them with C body units as you can get larger bars in that way. Definetly get rid of the rubber isolaters. Also, pitch the B body lower control arms for A body units. They are a half inch longer and will give you more caster/camber than the B body units.