K Frame question and steering

There really isn't much weight difference between a 225 & 318. If you put an aluminum intake and headers on the 318, the V-8 will weigh less.
The intent of the suspension on my Demon was to make it fun to drive on the street, particularly twisty back roads. To that end, I have kept the springs soft, and installed some very heavy duty (Monroe) gas shocks all around. There are also anti-sway bars fore and aft. Finally, because of the soft springs and big rubber (235/60-15), I fabricated a lateral Watts link to keep the axle from twisting the rear springs laterally and keep the axle from shifting.

The natural tendency of the A-body is to understeer. If you go with stiffer torsion bars, it will back off of that tendency to a certain extent. Conversely, if the rear leaves are stiffened, more understeer. Both statements assume that there are no changes made at the other end of the car.

Good handling, from a suspension view point is a matter of balance. Others have answered the issue of going with light torsion bars on the front. Is it possible to go to far the other way? Yes. When the front end is too stiff, it will "skip" in the turns and the transition from stuck down to slide will occur with less warning.