But Jim is wrong, it will run if the cam is a tooth off. Through inattention and lack of experience I managed to swap cams on an engine way back, got the timing out by a tooth and it ran quite well, other than a general lack of power. I've seen a few other examples of this since.
The procedure for checking cam timing is quite a bit different. Verify TDC and correct alignment of the timing marks on your engine first before worrying about this.
