In a general sense, yes it can be made to handle well enough to be fun to drive. I'd ask how serious are you about the intended usage? Street action, Goodguys autocross, open track days, serious race efforts? The seriousness of this answer should drive the seriousness of the effort to change the system.

A general rule of thumb is that a 1" relocation of the springs reduces its effective spring rate at the face of the drum by 5#. Figuring your springs are currently at a 28" spread, 18" was taken out of the overall width, or 9" per side. You would need a spring pack that is 45# heavier in rate than a pack located at the original position. Another general assumption; a mopar XHD leaf spring is around 150#, so you would need a 195# spring to duplicate the same resistance. That isn't real hard to find in a leaf pack.

Looking at your picture, it appears the original spring perches are still attached to the housing. I also assume that even for a backhalf job, there is a structural member where the links mount. Would it be possible to simply mount up a spring hanger to this area that aligns with the old spring perch?