Setting timing after head works

I HAVE A MAZDA(89) b2200, 2.2motor that did a head job on.I have set the bottom tdc mark, piston is up, dist. Pointed at no 1. My question is the position of the cam. The cam gear will go in any of four positions, what should I do to to put cam in right place. Tim, thanks your help is appreciated. Tmorgan140@aol. Com