I can tell you from experience I run 22 lbs of boost with 800 RWHP and it's safe. But say I was to hit it up to 6700 RPM's a few times. The bottom is gonna go. I've heard it from several others that have blown their engines doing this. I also run C16 in it. As far as I'm concerned the block could be better and I believe the pistons are a weak point. Mine I now run mostly race, some street.
As far as another block I would think it would all depend on how it's built. It also depends on your exact goals...meaning race only, street only, mostly street and race etc. Then if you are going to race will you road race or drag race. Several things to consider to get accomplish what your needs and wants are.
Powerhouse Racing and Performance
6332 Lee Ann Lane
United States, 34109