I plan on building one for next year and I would like to get an idea of the cost to get a used engine so that I can start doing some machine work and porting. Thanks in advance Moparts!

5.7L can be found pretty easily for $500 or so.

6.1L really isn't worth buying used...people think they're made of gold and want $4500 to $5000 even with
50,000-60,000 miles. For that much, might as well buy new.

here's a 5.7 for $600 which means they might take $500

http://detroit.craigslist.org/pts/1069848506.html

Here's the cheapest 6.1 I have ever seen, but most of them in the same shape are at least a grand to 1500 higher than this
click here for 6.1

The old books used to say 383s were very plentiful, that the factory made something over 3 million of them. The 5.7 has been made in even greater quantities than the 383, so they're out there for the taking and the prices aren't bad.

Try car-part.com