I tell all that ask that I see NO improvement from torsion bar to the coil spring.....The handling improvement comes from changes outlined earlier and by all means can be accomplished with the factory components....
except you will NOT have
30 lb weight reduction (not counting brake package, can be done on factory spindles)
the room generated by removing all the factory steering gear and torsion bars
the more precise feel of the modern rack and pinion steering
no idea either how some can claim a 120lb weight savings going to a coil over conversion.....the whole (manual steer) factory package only weighs 118lbs
it is what it is....