Doesnt matter, if it was in an engine and run at all, even for a few minutes, and you take it out and put the cam and lifters in another engine, it wont wear the same, and that's the problem. I personally wouldnt do it, but go for it if you feel confident. I would just hate to see you trash a new engine trying to save a few bucks. The lifters and cam lobes wear together during break-in, it only takes a few minutes. So the short run time on the cam wont guarantee you anything. Im sure you dont want to offend your friend, but make a call to a couple other shops and ask their opinion. Just a thought.