I've always tried to look at an engine swap at more angles than just horsepower gains... there is also ease of maintenance, availability of parts, replacement part cost, and so forth.

Yeah you can fit an K series in an EG, fairly easily, but it's cramped for space like you said, and quite a bit more expensive than your standard B series swap.

If you're looking for horsepower and speed, then the Special K is where it's at.

But if you want an engine that's easier to fix on the side of the road, a ton cheaper, and almost as good... build a B series and drop it in.