I do most of what I do by talking to my local buds and finding out what is out there to trade. I currently have an '04 Mustang efi 302 coming to me from across the street and am looking at several 460 engines. I work it thataway...
Generally I wait and listen until something I hear turns a lightbulb on upstairs - and then figure a deal from there. So far I've come out cash ahead almost every dang time!
Except over those stupid dirt bikes...