516 heads with double valve springs ?

RB,
1993 is hardly the ice age when springs in IC engines go back to before the model T.
Comp Cams is probably the most well known company for BH springs among the cam companies & there are NONE listed in their 1997 catalog.
If you have to buy new springs, then you are spending money; so they do offer an advantage, & more than one advantage.
Nice try, but no cigar....