This just showed up in my searchin' this morning:
http://corvallis.craigslist.org/cto/5184282262.html
"1972 Chevy flatbed dump truck -- $1500" in Corvallis, CA (specific town is Lebanon)
"72 Chevy C50 with a newer detachable electric dump bed (16 feet) with good wood on it. 4 bolt main 350 runs ok, could use a carb cleaning but always runs with a bit of ether to get it started. The transmission is a four speed with Eaton 2 speed rear end. The cab has a lot of rust in it and the brakes could use some attention but it has been driven recently."
(503) 523-7325