I did all the things you mention with the K frame and torsion bars.
Converted to Wilwood disk brakes, upgraded all suspension, front and rear, Borgeson power steering box, 340 engine, auto to A-833 plus Gear Vendors Overdrive and 8.75 diff with 3:55 limited slip.
The suspension and disc brake upgrade was relatively easy. Getting my Doug's Header pipe to fit between the torsion bar and mini starter has been a bear.
