I use Search Tempest and Crazedlist a lot. The market for drop-outs just seems different here. I've actually been looking/trolling for a 5.3 for quite a while now, and I just haven't came across a decent deal in Colorado/Wyoming. The yards in this state are smoking everything in site, and think their stuff is gold. And I don't have the time to go pull one at a yard myself, not with mine and my wife's schedules.
This is typical of what Craigslist usually has to offer around here:
http://denver.craigslist.org/pts/1268217564.html
I'm one to tell a person to keep looking too, that those deals are out there. But I haven't found one yet in my area. And if I do, it's usually too far away to make it worth the cost.
For what I
have found, the purchase price of a 6.0 is kind of out of my budget range for this project. That, and my main goal is economy first with performance being an added bonus. But if I was trying to build a tire destroyer I would definitely be hunting for a 6.0 for sure. I personally like the 5.3, it has everything I'm looking for.