my understanding is that it's a LOT easier to turbo an EFI car, but I know there's a lot of turbo'd carb'd motors out there. First thing you'll need to figure out is if you're gonna go blow-through or draw-though. Blow-through has the advantage of keeping your carb in it's stock location, but (I think) you have to get a special carb; draw through allows you to keep your carb (rejetted, of course), but you'll have to relocate it. Also, with a draw-though, you have the disadvantage of of having fuel going through a VERY hot turbo.
There's a lot of science to it, and people that know a LOT more than I.