FMX, Are you asking about GM crate engines in general, or that specific engine?

I couldn't comment on building from scratch, as I have never done it yet. One of my reasons to use a crate was due to time constraints. Some of it depends on what you think your time is worth and how you want to spend it.

Check the fine print on the warranty, I believe the longer ones stipulate that they would be installed by a mechanic.

Not too long ago I purchased a new 290HP/350 from ATK. It was pretty sweet having a brand new engine delivered right to my house. I wish I had done a little more research before I got it. I have a buddy that works for a local parts warehouse that could have saved me literally hundreds in costs, (markup and shipping). I also understand that your local GM parts dealer can sometimes have the best prices on GM-Performance parts.

I've also found that Salee Chevrolet has some of the better information on the net.