Dollars to doughnuts, the Sansui will sound better. The SA-x00 series Technics just aren't up to their contemporary Japanese massmarket brethren in any way shape or form as far as I am concerned. The Technics receivers of that model era sound thin and two-dimensional to me. Pioneer rather famously directly contrasted the construction values of the Technics of that era with their own receivers.
YMMV, of course. I don't have a dog in this fight; there's lots of better sounding stuff than either (again, to my ears and tastes).