Are you talking about an offset bearing that runs on a different part of the axle shaft or a sleeve repair kit for the axle shaft that goes over the bearing area where it's pitted? The offset bearing should use the same seal as the stock bearing. If it's a sleeve kit, it probably uses a seal with a bigger inside diameter than stock to accomodate the sleeve thickness. If it's an oddball seal that the sleeve company had made special, you may be out of luck unless you know the company and they're willing to sell the seals separately.