is it worth installing cam in stock 318?

Depends on the engine and trans condition....is it a good engine ready to go, or a rebuildable 'core', or totally trashed out? How is the body and other parts? It could be a deal, or not. If it includes the bellhousing and clutch pedals and complete linkage, and the engine is a good core and you get a lot of other parts that you can use for spares or sell off, then it may be a good deal. But at that price, I would be expecting a full engine rebuild. I get the impression that you can't afford that.

Well as far as I know its running and in good condition. Mine only have 73.000miles on it and runs excellent, I dont expect the other one to have such low millage. The questions is, if I ever want to sell it, will someone apreciate it to have it as it came from factory with original engine or something more powerful but custom? When I bought the car I told him that I rather have stick and he offered me the whole 340 4 speed tranny for 1k with all parts I need. But that car will not see the road again, the fenders are gone and he was planning to use the engine for his 68 Dart. I think if I go there with 1500 he will sell me the other one, or maybe even less so I can use the engine and everything else.

Its not really about if I can afford something or not, its about priorities. Im not a fanatic of anything as cars or anything else. I am interested in lots of things like travel, so it just have to be a balance. If I have a good month with business, buying the other demon would be an option. I would LOVE to have a V8 with stick. I dont like automatic at all.