250-500cc Husqvarna Wr 250-300 Sprocket

Hello everyone, I'm michele and I write from Italy, it's my first post even if I've been a member for some time, so sorry for not good English. In this period of reading the forum I really appreciated its content and now I have a question (which I think has not treated anyone yet) concerning the sprocket of the Husqvarna WR 250-300.
While I was changing the front sprocket I saw that it is not symmetrical, i mean if you mount it as opposed to how it is from factory you have the sprocket and the chain that sit outward about 5 millimeters more than before. So I was wondering if you mount it like described, also moving the rear sprocket more external of 5 millimeters, the transmission is aligned with a gain of 5 millimeters of space from the wheel. More interesting is the possibility of mounting a SMR rear wheel without alignment issue. The only doubt is if the gearbox would be ruined by doing this change .... so I wanted to know what you think and if someone has already done it.