Mainly for simplicity. It would be way easier to wire and plumb. Plus it uses more common parts than the sc 3.8.
After doing some research I don't think the 470 is the answer either. I don't know why I'm second guessing myself, I was just out in the garage looking at all the shit on the 3.8 and it just scares me.
"Takes a lickin' and keeps on tickin'!"