The timing-cover holes are larger than the bolt diameter, hence, the bolts do not provide correct placement of the cover. You must be sure that the flat portions at the bottom of the timing cover are exactly level with the oil-pan rails. This portion of the timing cover becomes part of the pan rail, and if they are not even, you’ll have an oil leak here. Also, if the cover is not in the correct position, your front seal will be off-center with respect to the crank snout. In this condition, the seal will be damaged when the engine is run, and you’ll have two leaks up front.