craigs list, people's alley... go for a drive, see if you can find one that looks like it hasn't moved for a while... go knock on the door of the house it's sitting at ask them if they would be interested in selling it... these people would probably be the cheapest way possible as a little extra cash and more room in the driveway is always nice to have, especially when someone one offers both to you...
FWIW, i bought an 88 f-250 with a 460, manual trans, manual t/c manual hubs, super cab long box, running driving, for $460 and drove it for about a year, maybe more, did nothing more than the hubs (kind of, once) replaced the battery, and filled the tank...