Depends on how much $$ you have to spend. The Mopar Crate motor's are very affordable, but you get what you pay for. I have 402/435 crate motor that was 5k, but I have 2500 in balancing and head work. If I had to do it over again, I would buy a good block and go to Dick Landy
http://dicklandy.com/index.htm or
http://www.raybarton.com/ tell them what I want, ask them to build it right the first time, and live happily ever after....