Later model 3.8 swap in an "A" body

I ponder these same possibilities sometimes. I could buy a 93 Dakota pickup ( for example ) and transplant that V6 / overdrive drive train into my classic car but... the car isn't my daily driver so it doesn't burn a lot of fuel at any price.
Neither does my daily driver ( POS 91 Geo Prism ).
I wont say I enjoy driving the Geo but the 5 bucks per gallon is constant no matter what its pumped into or rate its burned out. So I drive for cheap when I need to and splurge to drive and enjoy the classic when I want to.
Friends and neighbors who fish, golf, or whatever, spend a lot more on their hobby than I spend on mine.
One my factor that sways me from doing anything different, The more time my classic spends in the streets and public parking lots the more likely it will be beat on by John Q. Public.