I've read that it is Gary Stanton building the 426 and that Ray Barton builds the 472 & 528. From what I've read all the 2008 and newer crate engines are much better than the earlier Cummings built engines. Apparently Mopar spent a pile of money on new tooling to improve the quality of the parts and then switched to these builders to improve on the quality of the assembly process. A quick way to spot a 2008 and newer block is to look for the extra frost plugs, which are on the front of the block on either side of the water pump.
I have a 2009 built 426 crate Hemi that I bought from my local Dodge dealer. I haven't had any problems with it yet, but that maybe cause it's still strapped to the crate on the garage floor.