I believe if you turn the crankshaft until the timing mark on the balancer/pulley lines up with the 0-degree mark on the lower timing cover, the timing mark on the cam sprocket should also be lined up with the mark on the rear cover. Remember, the number 1 cylinder should be on it's compression stroke at this point. I haven't checked this so I could be wrong but I seem to recall the last time I did a t-belt, this was true. I've always replaced the t-belts with the covers off. If your engine has the distributor on the side of the engine, you'll need to check the position of the auxiliary shaft also.