The engine in the picture is a 46 with open bearings and a seal on each end of the crank..There is another 46, identical Huskqvarna crank, different case..The case on the other has numbers on the bottom--530-049794 and 3254...the bolt pattern on the second case is wider to accomodate the different bearings used..the crank seals are part of the bearing and completly enclose the bearing, making a wider bolt pattern necessary due to the larger diameter bearing...the cases are otherwise the same...