Welcome aboard!
Another place where you can find these engines are in the country right to the east of you but not as cheap as they seem to be in America,the ones in Swedish wreckingyards tend to be somewhat expensive but atleast many of them are marked as tested and ok(if we want to trust that is a different story)its alitle anoying to have to check all listings individualy but there may be a way aorund that. Most wreckingyards list there stuff on:
Bildelsbasen.se - Sveriges största utbud av bildelar You can probably figure out the Swedish text, ohh wait its also available in Norwegian,see below:
Bildelsbasen.se - Nye og brukte bildeler
You can also check out Blocket for adds from both private persons and bussines,have seen a few 5.7s for sale on there,most to expensive in my opinion but a few that has been very reasonable priced.
Link directly to search for adds,you may figure out some better searchterm but Hemi have brought up more than a few over the years, even thougth the good priced ones are not as comon.
Hela Sverige > Bildelar & biltillbehör | Blocket