Re: Another Big Twin Observation…. Home › Forum › Ask A Member › Another Big Twin Observation…. › Re: Another Big Twin Observation…. frankrUS Member - 1 Year (includes $3 online payment fee)Replies: 6715Topics: 51 August 10, 2018 at 12:00 pm #80914 No, that "L" means it left the factory as a long shaft. If there was a letter suffix, it would follow the "18". As for the rest of the question, I have no way of knowing without the parts book.