Randy, I would do that just yet. The difference may mean nothing. It depends on how far each of the pulleys seat on the shafts. My 181 fits and lines up perfectly. I dont think I am going to pull it to compare to the factory pulley though. If there is enough depth on the crank for the LET to slide on the shaft and line up correctly, you wouldnt need to do anything. If the pulley is tight on the shaft and it binds before it seats all the way, you have a problem with alignment. Just my observations. Contact Jerry for advice.

MikeR