Stupid question? Can I replace my torsionbars and leafsprings for coilovers?

No, and yes;
and why would you want to?
Our Mopars have one of the finest oem suspensions of the era and beyond.
You would have to spend a lot of money, and or do a lot of work, to have coilovers at both ends.
And when the shocks wear out; more work.

Mopars were specifically designed to get away from coilovers.
They were designed so that the shocks can be shocks and the springs can be springs.