some people get insanely lucky and pick up 350s for a song... keep in mind that ideally you are going to need to replace the top end, intake clamp, possibly bearings, seals, reseal the lower bearing cap, and ideally put a muffler suppose on... and a myriad of other things. you can't just buy them and run them ....they have inherent issues that need to be addressed. even if you pick up a nice one for $150, you may still end up spending more than you'd like. if you can buy from someone that knows what they are doing and has done the upgrades you may be better off.
look for the metal intake clamp...a necessity
look for the metal intake clamp...a necessity