I bought a 383 blue print fully dressed this spring. I just fired it up a few weeks ago. I haven't had any issues with the motor. I did have to swap out some springs in the dizzy and set the timing to their specs. I did have to rotate the eddy fuel pump to work with subframe clearance.
I've put about 500 miles on the motor and it runs great, no leaks. There was some confusion on what flywheel to use one paper they sent said to use a weighted flywheel and another says not to use a weighted wheel.
No matter where you get your motor you will be rolling the dice....just hope who ever you buy from will stand behind their warranty.